diff --git a/README.md b/README.md
index 5a347a68..762d7396 100644
--- a/README.md
+++ b/README.md
@@ -32,12 +32,13 @@ For more information, tutorials, etc., please view the project's [wiki](https://
 - [x] Provide assistance in developing Shopify apps with Laravel
 - [x] Integration with Shopify API
 - [x] Authentication & installation for shops
-- [x] Billing integration built-in for single and recurring application charges
+- [x] Plan & billing integration for single, recurring, and usage-types
 - [x] Tracking charges to a shop (recurring, single, usage, etc) with trial support
 - [x] Auto install app webhooks and scripttags thorugh background jobs
 - [x] Provide basic ESDK views
 - [x] Handles and processes incoming webhooks
 - [x] Handles and verifies incoming app proxy requests
+- [x] Namespacing abilities to run multiple apps on the same database
 
 ## Documentation
 
diff --git a/src/ShopifyApp/Libraries/BillingPlan.php b/src/ShopifyApp/Libraries/BillingPlan.php
index 3a202067..71baaf05 100644
--- a/src/ShopifyApp/Libraries/BillingPlan.php
+++ b/src/ShopifyApp/Libraries/BillingPlan.php
@@ -3,6 +3,7 @@
 namespace OhMyBrew\ShopifyApp\Libraries;
 
 use Exception;
+use OhMyBrew\ShopifyApp\Models\Plan;
 use OhMyBrew\ShopifyApp\Models\Shop;
 
 class BillingPlan
@@ -15,11 +16,11 @@ class BillingPlan
     protected $shop;
 
     /**
-     * The plan details for Shopify.
+     * The plan to use.
      *
-     * @var array
+     * @var \OhMyBrew\ShopifyApp\Models\Plan
      */
-    protected $details;
+    protected $plan;
 
     /**
      * The charge ID.
@@ -28,48 +29,18 @@ class BillingPlan
      */
     protected $chargeId;
 
-    /**
-     * The charge type.
-     *
-     * @var string
-     */
-    protected $chargeType;
-
     /**
      * Constructor for billing plan class.
      *
-     * @param Shop   $shop       The shop to target for billing.
-     * @param string $chargeType The type of charge for the plan (single or recurring).
+     * @param Shop $shop The shop to target for billing.
+     * @param Plan $plan The plan from the database.
      *
      * @return $this
      */
-    public function __construct(Shop $shop, string $chargeType = 'recurring')
+    public function __construct(Shop $shop, Plan $plan)
     {
         $this->shop = $shop;
-        $this->chargeType = $chargeType === 'single' ? 'application_charge' : 'recurring_application_charge';
-
-        return $this;
-    }
-
-    /**
-     * Sets the plan.
-     *
-     * @param array $plan The plan details.
-     *                    $plan = [
-     *                    'name'          => (string) Plan name.
-     *                    'price'         => (float) Plan price. Required.
-     *                    'test'          => (boolean) Test mode or not.
-     *                    'trial_days'    => (int) Plan trial period in days.
-     *                    'return_url'    => (string) URL to handle response for acceptance or decline or billing. Required.
-     *                    'capped_amount' => (float) Capped price if using UsageCharge API.
-     *                    'terms'         => (string) Terms for the usage. Required if using capped_amount.
-     *                    ]
-     *
-     * @return $this
-     */
-    public function setDetails(array $details)
-    {
-        $this->details = $details;
+        $this->plan = $plan;
 
         return $this;
     }
@@ -103,15 +74,15 @@ public function getCharge()
         // Run API to grab details
         return $this->shop->api()->rest(
             'GET',
-            "/admin/{$this->chargeType}s/{$this->chargeId}.json"
-        )->body->{$this->chargeType};
+            "/admin/{$this->plan->typeAsString(true)}/{$this->chargeId}.json"
+        )->body->{$this->plan->typeAsString()};
     }
 
     /**
      * Activates a plan to the shop.
      *
      * Example usage:
-     * (new BillingPlan([shop], 'recurring'))->setChargeId(request('charge_id'))->activate();
+     * (new BillingPlan([shop], [plan]))->setChargeId(request('charge_id'))->activate();
      *
      * @return object
      */
@@ -125,47 +96,52 @@ public function activate()
         // Activate and return the API response
         return $this->shop->api()->rest(
             'POST',
-            "/admin/{$this->chargeType}s/{$this->chargeId}/activate.json"
-        )->body->{$this->chargeType};
+            "/admin/{$this->plan->typeAsString(true)}/{$this->chargeId}/activate.json"
+        )->body->{$this->plan->typeAsString()};
     }
 
     /**
-     * Gets the confirmation URL to redirect the customer to.
-     * This URL sends them to Shopify's billing page.
-     *
-     * Example usage:
-     * (new BillingPlan([shop], 'recurring'))->setDetails($plan)->getConfirmationUrl();
+     * Returns the charge params sent with the post request.
      *
-     * @return string
+     * @return array
      */
-    public function getConfirmationUrl()
+    public function getChargeParams()
     {
-        // Check if we have plan details
-        if (!is_array($this->details)) {
-            throw new Exception('Plan details are missing for confirmation URL request.');
-        }
-
         // Build the charge array
         $chargeDetails = [
-            'test'          => isset($this->details['test']) ? $this->details['test'] : false,
-            'trial_days'    => isset($this->details['trial_days']) ? $this->details['trial_days'] : 0,
-            'name'          => $this->details['name'],
-            'price'         => $this->details['price'],
-            'return_url'    => $this->details['return_url'],
+            'test'          => $this->plan->isTest(),
+            'trial_days'    => $this->plan->hasTrial() ? $this->plan->trial_days : 0,
+            'name'          => $this->plan->name,
+            'price'         => $this->plan->price,
+            'return_url'    => secure_url(config('shopify-app.billing_redirect'), ['plan_id' => $this->plan->id]),
         ];
 
         // Handle capped amounts for UsageCharge API
-        if (isset($this->details['capped_amount'])) {
-            $chargeDetails['capped_amount'] = $this->details['capped_amount'];
-            $chargeDetails['terms'] = $this->details['terms'];
+        if (isset($this->plan->capped_amount)) {
+            $chargeDetails['capped_amount'] = $this->plan->capped_amount;
+            $chargeDetails['terms'] = $this->plan->terms;
         }
 
+        return $chargeDetails;
+    }
+
+    /**
+     * Gets the confirmation URL to redirect the customer to.
+     * This URL sends them to Shopify's billing page.
+     *
+     * Example usage:
+     * (new BillingPlan([shop], [plan]))->setDetails($plan)->getConfirmationUrl();
+     *
+     * @return string
+     */
+    public function getConfirmationUrl()
+    {
         // Begin the charge request
         $charge = $this->shop->api()->rest(
             'POST',
-            "/admin/{$this->chargeType}s.json",
-            ["{$this->chargeType}" => $chargeDetails]
-        )->body->{$this->chargeType};
+            "/admin/{$this->plan->typeAsString(true)}.json",
+            ["{$this->plan->typeAsString()}" => $this->getChargeParams()]
+        )->body->{$this->plan->typeAsString()};
 
         return $charge->confirmation_url;
     }
diff --git a/src/ShopifyApp/Middleware/AuthProxy.php b/src/ShopifyApp/Middleware/AuthProxy.php
index 7bef19d9..d9359a11 100644
--- a/src/ShopifyApp/Middleware/AuthProxy.php
+++ b/src/ShopifyApp/Middleware/AuthProxy.php
@@ -18,23 +18,13 @@ class AuthProxy
      */
     public function handle(Request $request, Closure $next)
     {
-        // Grab the data we need
+        // Grab the data we need, remove signature since its not part of the signature calculation
         $query = request()->all();
         $signature = $query['signature'];
-
-        // Remove signature since its not part of the signature calculation, sort it
         unset($query['signature']);
-        ksort($query);
-
-        // Build a query string without query characters
-        $queryCompiled = [];
-        foreach ($query as $key => $value) {
-            $queryCompiled[] = "{$key}=".(is_array($value) ? implode($value, ',') : $value);
-        }
-        $queryJoined = implode($queryCompiled, '');
 
         // Build a local signature
-        $signatureLocal = hash_hmac('sha256', $queryJoined, config('shopify-app.api_secret'));
+        $signatureLocal = ShopifyApp::createHmac(['data' => $query, 'buildQuery' => true]);
         if ($signature !== $signatureLocal || !isset($query['shop'])) {
             // Issue with HMAC or missing shop header
             abort(401, 'Invalid proxy signature');
diff --git a/src/ShopifyApp/Middleware/AuthWebhook.php b/src/ShopifyApp/Middleware/AuthWebhook.php
index 8615da34..943d06fc 100644
--- a/src/ShopifyApp/Middleware/AuthWebhook.php
+++ b/src/ShopifyApp/Middleware/AuthWebhook.php
@@ -4,6 +4,7 @@
 
 use Closure;
 use Illuminate\Http\Request;
+use OhMyBrew\ShopifyApp\Facades\ShopifyApp;
 
 class AuthWebhook
 {
@@ -21,8 +22,7 @@ public function handle(Request $request, Closure $next)
         $shop = request()->header('x-shopify-shop-domain');
         $data = request()->getContent();
 
-        // From https://help.shopify.com/api/getting-started/webhooks#verify-webhook
-        $hmacLocal = base64_encode(hash_hmac('sha256', $data, config('shopify-app.api_secret'), true));
+        $hmacLocal = ShopifyApp::createHmac(['data' => $data, 'raw' => true, 'encode' => true]);
         if (!hash_equals($hmac, $hmacLocal) || empty($shop)) {
             // Issue with HMAC or missing shop header
             abort(401, 'Invalid webhook signature');
diff --git a/src/ShopifyApp/Middleware/Billable.php b/src/ShopifyApp/Middleware/Billable.php
index 3d85557d..0a27be57 100644
--- a/src/ShopifyApp/Middleware/Billable.php
+++ b/src/ShopifyApp/Middleware/Billable.php
@@ -20,17 +20,8 @@ class Billable
     public function handle(Request $request, Closure $next)
     {
         if (config('shopify-app.billing_enabled') === true) {
-            // Grab the shop and last recurring or one-time charge
             $shop = ShopifyApp::shop();
-            $lastCharge = $shop->charges()
-                ->whereIn('type', [Charge::CHARGE_RECURRING, Charge::CHARGE_ONETIME])
-                ->orderBy('created_at', 'desc')
-                ->first();
-
-            if (
-                !$shop->isGrandfathered() &&
-                (is_null($lastCharge) || $lastCharge->isDeclined() || $lastCharge->isCancelled())
-            ) {
+            if (!$shop->isFreemium() && !$shop->isGrandfathered() && !$shop->plan) {
                 // They're not grandfathered in, and there is no charge or charge was declined... redirect to billing
                 return redirect()->route('billing');
             }
diff --git a/src/ShopifyApp/Models/Charge.php b/src/ShopifyApp/Models/Charge.php
index 34912e6e..3b2caacb 100644
--- a/src/ShopifyApp/Models/Charge.php
+++ b/src/ShopifyApp/Models/Charge.php
@@ -16,6 +16,32 @@ class Charge extends Model
     const CHARGE_USAGE = 3;
     const CHARGE_CREDIT = 4;
 
+    /**
+     * The attributes that are mass assignable.
+     *
+     * @var array
+     */
+    protected $fillable = [
+        'type',
+        'shop_id',
+        'charge_id',
+        'plan_id',
+    ];
+
+    /**
+     * The attributes that should be casted to native types.
+     *
+     * @var array
+     */
+    protected $casts = [
+        'type'          => 'int',
+        'test'          => 'bool',
+        'charge_id'     => 'int',
+        'shop_id'       => 'int',
+        'capped_amount' => 'float',
+        'price'         => 'float',
+    ];
+
     /**
      * The attributes that should be mutated to dates.
      *
@@ -33,6 +59,16 @@ public function shop()
         return $this->belongsTo('OhMyBrew\ShopifyApp\Models\Shop');
     }
 
+    /**
+     * Gets the plan.
+     *
+     * @return \OhMyBrew\ShopifyApp\Models\Plan
+     */
+    public function plan()
+    {
+        return $this->belongsTo('OhMyBrew\ShopifyApp\Models\Plan');
+    }
+
     /**
      * Gets the charge's data from Shopify.
      *
diff --git a/src/ShopifyApp/Models/Plan.php b/src/ShopifyApp/Models/Plan.php
new file mode 100644
index 00000000..8c4edac0
--- /dev/null
+++ b/src/ShopifyApp/Models/Plan.php
@@ -0,0 +1,88 @@
+<?php
+
+namespace OhMyBrew\ShopifyApp\Models;
+
+use Illuminate\Database\Eloquent\Model;
+
+class Plan extends Model
+{
+    // Types of plans
+    const PLAN_RECURRING = 1;
+    const PLAN_ONETIME = 2;
+
+    /**
+     * The attributes that should be casted to native types.
+     *
+     * @var array
+     */
+    protected $casts = [
+        'type'          => 'int',
+        'test'          => 'bool',
+        'on_install'    => 'bool',
+        'capped_amount' => 'float',
+        'price'         => 'float',
+    ];
+
+    /**
+     * Get charges.
+     *
+     * @return \Illuminate\Database\Eloquent\Collection
+     */
+    public function charges()
+    {
+        return $this->hasMany('OhMyBrew\ShopifyApp\Models\Charge');
+    }
+
+    /**
+     * Returns the plan type as a string (for API).
+     *
+     * @param bool $plural Return the plural form or not.
+     *
+     * @return string
+     */
+    public function typeAsString($plural = false)
+    {
+        $type = null;
+        switch ($this->type) {
+            case self::PLAN_ONETIME:
+                $type = 'application_charge';
+                break;
+            default:
+            case self::PLAN_RECURRING:
+                $type = 'recurring_application_charge';
+                break;
+        }
+
+        return $plural ? "{$type}s" : $type;
+    }
+
+    /**
+     * Checks if this plan has a trial.
+     *
+     * @return bool
+     */
+    public function hasTrial()
+    {
+        return $this->trial_days !== null && $this->trial_days > 0;
+    }
+
+    /**
+     * Checks if this plan should be presented on install.
+     *
+     * @return bool
+     */
+    public function isOnInstall()
+    {
+        return (bool) $this->on_install;
+    }
+
+    /**
+     * Checks if the plan is a test.
+     *
+     * @return bool
+     */
+    public function isTest()
+    {
+        return (bool) $this->test;
+    }
+}
diff --git a/src/ShopifyApp/Models/Shop.php b/src/ShopifyApp/Models/Shop.php
index eddd1d54..c651f2b9 100644
--- a/src/ShopifyApp/Models/Shop.php
+++ b/src/ShopifyApp/Models/Shop.php
@@ -23,6 +23,16 @@ class Shop extends Model
         'namespace',
     ];
 
+    /**
+     * The attributes that should be casted to native types.
+     *
+     * @var array
+     */
+    protected $casts = [
+        'grandfathered' => 'bool',
+        'freemium'      => 'bool',
+    ];
+
     /**
      * The attributes that should be mutated to dates.
      *
@@ -97,4 +107,24 @@ public function hasCharges()
     {
         return $this->charges->isNotEmpty();
     }
+
+    /**
+     * Gets the plan.
+     *
+     * @return \OhMyBrew\ShopifyApp\Models\Plan
+     */
+    public function plan()
+    {
+        return $this->belongsTo('OhMyBrew\ShopifyApp\Models\Plan');
+    }
+
+    /**
+     * Checks if the shop is freemium.
+     *
+     * @return bool
+     */
+    public function isFreemium()
+    {
+        return ((bool) $this->freemium) === true;
+    }
 }
diff --git a/src/ShopifyApp/Observers/ShopObserver.php b/src/ShopifyApp/Observers/ShopObserver.php
index 006b4f1e..e3215b87 100644
--- a/src/ShopifyApp/Observers/ShopObserver.php
+++ b/src/ShopifyApp/Observers/ShopObserver.php
@@ -19,5 +19,10 @@ public function creating(Shop $shop)
             // Automatically add the current namespace to new records
             $shop->namespace = config('shopify-app.namespace');
         }
+
+        if (config('shopify-app.billing_freemium_enabled') === true && !isset($shop->freemium)) {
+            // Add the freemium flag to the shop
+            $shop->freemium = true;
+        }
     }
 }
diff --git a/src/ShopifyApp/ShopifyApp.php b/src/ShopifyApp/ShopifyApp.php
index fd121748..93a6cf64 100644
--- a/src/ShopifyApp/ShopifyApp.php
+++ b/src/ShopifyApp/ShopifyApp.php
@@ -92,4 +92,37 @@ public function sanitizeShopDomain($domain)
         // Return the host after cleaned up
         return parse_url("http://{$domain}", PHP_URL_HOST);
     }
+
+    /**
+     * HMAC creation helper.
+     *
+     * @param array $opts
+     *
+     * @return string
+     */
+    public function createHmac(array $opts)
+    {
+        // Setup defaults
+        $data = $opts['data'];
+        $raw = $opts['raw'] ?? false;
+        $buildQuery = $opts['buildQuery'] ?? false;
+        $encode = $opts['encode'] ?? false;
+        $secret = $opts['secret'] ?? config('shopify-app.api_secret');
+
+        if ($buildQuery) {
+            //Query params must be sorted and compiled
+            ksort($data);
+            $queryCompiled = [];
+            foreach ($data as $key => $value) {
+                $queryCompiled[] = "{$key}=".(is_array($value) ? implode($value, ',') : $value);
+            }
+            $data = implode($queryCompiled, '');
+        }
+
+        // Create the hmac all based on the secret
+        $hmac = hash_hmac('sha256', $data, $secret, $raw);
+
+        // Return based on options
+        return $encode ? base64_encode($hmac) : $hmac;
+    }
 }
diff --git a/src/ShopifyApp/Traits/BillingControllerTrait.php b/src/ShopifyApp/Traits/BillingControllerTrait.php
index 8a44db9f..5b812863 100644
--- a/src/ShopifyApp/Traits/BillingControllerTrait.php
+++ b/src/ShopifyApp/Traits/BillingControllerTrait.php
@@ -6,6 +6,7 @@
 use OhMyBrew\ShopifyApp\Facades\ShopifyApp;
 use OhMyBrew\ShopifyApp\Libraries\BillingPlan;
 use OhMyBrew\ShopifyApp\Models\Charge;
+use OhMyBrew\ShopifyApp\Models\Plan;
 use OhMyBrew\ShopifyApp\Models\Shop;
 
 trait BillingControllerTrait
@@ -13,51 +14,57 @@ trait BillingControllerTrait
     /**
      * Redirects to billing screen for Shopify.
      *
+     * @param int|null $planId The plan's ID.
+     *
      * @return \Illuminate\Http\Response
      */
-    public function index()
+    public function index($planId = null)
     {
         // Get the confirmation URL
         $shop = ShopifyApp::shop();
-        $plan = new BillingPlan($shop, $this->chargeType());
-        $plan->setDetails($this->planDetails($shop));
+        $billingPlan = new BillingPlan($shop, $this->getPlan($planId));
 
         // Do a fullpage redirect
         return view('shopify-app::billing.fullpage_redirect', [
-            'url' => $plan->getConfirmationUrl(),
+            'url' => $billingPlan->getConfirmationUrl(),
         ]);
     }
 
     /**
      * Processes the response from the customer.
      *
-     * @return void
+     * @param int|null $planId The plan's ID.
+     *
+     * @return \Illuminate\Http\Response
      */
-    public function process()
+    public function process($planId = null)
     {
         // Setup the shop and get the charge ID passed in
         $shop = ShopifyApp::shop();
         $chargeId = request('charge_id');
 
         // Setup the plan and get the charge
-        $plan = new BillingPlan($shop, $this->chargeType());
-        $plan->setChargeId($chargeId);
-        $status = $plan->getCharge()->status;
+        $plan = $this->getPlan($planId);
+        $billingPlan = new BillingPlan($shop, $plan);
+        $billingPlan->setChargeId($chargeId);
+        $status = $billingPlan->getCharge()->status;
 
         // Grab the plan detailed used
-        $planDetails = $this->planDetails($shop);
+        $planDetails = $billingPlan->getChargeParams();
         unset($planDetails['return_url']);
 
         // Create a charge (regardless of the status)
-        $charge = new Charge();
-        $charge->type = $this->chargeType() === 'recurring' ? Charge::CHARGE_RECURRING : Charge::CHARGE_ONETIME;
-        $charge->charge_id = $chargeId;
-        $charge->status = $status;
+        $charge = Charge::firstOrNew([
+            'type'      => $plan->type,
+            'shop_id'   => $shop->id,
+            'plan_id'   => $plan->id,
+            'charge_id' => $chargeId,
+        ]);
 
         // Check the customer's answer to the billing
         if ($status === 'accepted') {
             // Activate and add details to our charge
-            $response = $plan->activate();
+            $response = $billingPlan->activate();
             $charge->status = $response->status;
             $charge->billing_on = $response->billing_on;
             $charge->trial_ends_on = $response->trial_ends_on;
@@ -79,68 +86,92 @@ public function process()
         foreach ($planDetails as $key => $value) {
             $charge->{$key} = $value;
         }
-
-        // Save and link to the shop
-        $shop->charges()->save($charge);
+        $charge->save();
 
         if ($status === 'declined') {
             // Show the error... don't allow access
-            return abort(403, 'It seems you have declined the billing charge for this application');
+            return view('shopify-app::billing.error', ['message' => 'It seems you have declined the billing charge for this application']);
         }
 
-        // All good... go to homepage of app
+        // All good, update the shop's plan and take them off freeium (if applicable)
+        $shop->freemium = false;
+        $shop->plan_id = $plan->id;
+        $shop->save();
+
+        // Go to homepage of app
         return redirect()->route('home');
     }
 
     /**
-     * Base plan to use for billing. Setup as a function so its patchable.
-     * Checks for cancelled charge within trial day limit, and issues
-     * a new trial days number depending on the result for shops who
-     * resinstall the app.
+     * Allows for setting a usage charge.
      *
-     * @param object $shop The shop object.
-     *
-     * @return array
+     * @return \Illuminate\Http\Response
      */
-    protected function planDetails(Shop $shop)
+    public function usageCharge()
     {
-        // Initial plan details
-        $plan = [
-            'name'       => config('shopify-app.billing_plan'),
-            'price'      => config('shopify-app.billing_price'),
-            'test'       => config('shopify-app.billing_test'),
-            'return_url' => url(config('shopify-app.billing_redirect')),
-        ];
-
-        // Handle capped amounts for UsageCharge API
-        if (config('shopify-app.billing_capped_amount')) {
-            $plan['capped_amount'] = config('shopify-app.billing_capped_amount');
-            $plan['terms'] = config('shopify-app.billing_terms');
+        $shop = ShopifyApp::shop();
+        $lastCharge = $this->getLastCharge($shop);
+
+        if ($lastCharge->type !== Charge::CHARGE_RECURRING) {
+            // Charge is not recurring
+            return view('shopify-app::billing.error', ['message' => 'Can only create usage charges for recurring charge']);
         }
 
-        // Grab the last charge for the shop (if any) to determine if this shop
-        // reinstalled the app so we can issue new trial days based on result
-        $lastCharge = $this->getLastCharge($shop);
-        if ($lastCharge && $lastCharge->isCancelled()) {
-            // Return the new trial days, could result in 0
-            $plan['trial_days'] = $lastCharge->remainingTrialDaysFromCancel();
-        } else {
-            // Set initial trial days fromc config
-            $plan['trial_days'] = config('shopify-app.billing_trial_days');
+        // Get the input values needed
+        $data = request()->only(['price', 'description', 'redirect', 'signature']);
+        $signature = $data['signature'];
+        unset($data['signature']);
+
+        // Confirm the charge hasn't been tampered with
+        $signatureLocal = ShopifyApp::createHmac(['data' => $data, 'buildQuery' => true]);
+        if (!hash_equals($signature, $signatureLocal)) {
+            // Possible tampering
+            return view('shopify-app::billing.error', ['message' => 'Issue in creating usgae charge']);
         }
 
-        return $plan;
+        // Create the charge via API
+        $usageCharge = $shop->api()->rest(
+            'POST',
+            "/admin/recurring_application_charges/{$lastCharge->charge_id}/usage_charges.json",
+            [
+                'usage_charge' => [
+                    'price'       => $data['price'],
+                    'description' => $data['description'],
+                ],
+            ]
+        )->body->usage_charge;
+
+        // Create the charge in the database referencing the recurring charge
+        $charge = new Charge();
+        $charge->type = Charge::CHARGE_USAGE;
+        $charge->shop_id = $shop->id;
+        $charge->reference_charge = $lastCharge->charge_id;
+        $charge->charge_id = $usageCharge->id;
+        $charge->price = $usageCharge->price;
+        $charge->description = $usageCharge->description;
+        $charge->billing_on = $usageCharge->billing_on;
+        $charge->save();
+
+        // All done, return with success
+        return isset($data['redirect']) ? redirect($data['redirect']) : redirect()->back()->with('success', true);
     }
 
     /**
-     * Base charge type (single or recurring).
-     * Setup as a function so its patchable.
+     * Get the plan to use.
+     *
+     * @param int|null $planId The plan's ID.
      *
-     * @return string
+     * @return Plan
      */
-    protected function chargeType()
+    protected function getPlan($planId = null)
     {
-        return config('shopify-app.billing_type');
+        if ($planId === null) {
+            // Find the on-install plan
+            return Plan::where('on_install', true)->first();
+        }
+
+        // Find the plan passed to the method
+        return Plan::where('id', $planId)->first();
     }
 
     /**
@@ -154,6 +185,7 @@ protected function getLastCharge(Shop $shop)
     {
         return $shop->charges()
             ->whereIn('type', [Charge::CHARGE_RECURRING, Charge::CHARGE_ONETIME])
+            ->where('plan_id', $shop->plan_id)
             ->orderBy('created_at', 'desc')
             ->first();
     }
diff --git a/src/ShopifyApp/resources/config/shopify-app.php b/src/ShopifyApp/resources/config/shopify-app.php
index 21dda094..2b69b635 100644
--- a/src/ShopifyApp/resources/config/shopify-app.php
+++ b/src/ShopifyApp/resources/config/shopify-app.php
@@ -130,60 +130,15 @@
 
     /*
     |--------------------------------------------------------------------------
-    | Billing Type
+    | Enable Freemium Mode
     |--------------------------------------------------------------------------
     |
-    | Single charge or recurring charge.
-    | Simply use "single" for single, and "recurring" for recurring.
+    | Allow a shop use the app in "freemium" mode.
+    | Shop will get a `freemium` flag on their record in the table.
     |
     */
 
-    'billing_type' => env('SHOPIFY_BILLING_TYPE', 'recurring'),
-
-    /*
-    |--------------------------------------------------------------------------
-    | Billing Plan Name
-    |--------------------------------------------------------------------------
-    |
-    | The name of the plan which shows on the billing.
-    |
-    */
-
-    'billing_plan' => env('SHOPIFY_BILLING_PLAN_NAME', 'Base Plan'),
-
-    /*
-    |--------------------------------------------------------------------------
-    | Billing Price
-    |--------------------------------------------------------------------------
-    |
-    | The single or recurring price to charge the customer.
-    |
-    */
-
-    'billing_price' => (float) env('SHOPIFY_BILLING_PRICE', 0.00),
-
-    /*
-    |--------------------------------------------------------------------------
-    | Billing Trial
-    |--------------------------------------------------------------------------
-    |
-    | Trails days for the app. Set to 0 for no trial period.
-    |
-    */
-
-    'billing_trial_days' => (int) env('SHOPIFY_BILLING_TRIAL_DAYS', 7),
-
-    /*
-    |--------------------------------------------------------------------------
-    | Billing Test
-    |--------------------------------------------------------------------------
-    |
-    | Enable or disable test mode for billing.
-    | This is useful for development purposes, see Shopify's documentation.
-    |
-    */
-
-    'billing_test' => (bool) env('SHOPIFY_BILLING_TEST', false),
+    'billing_freemium_enabled' => (bool) env('SHOPIFY_BILLING_FREEMIUM_ENABLED', false),
 
     /*
     |--------------------------------------------------------------------------
@@ -197,28 +152,6 @@
 
     'billing_redirect' => env('SHOPIFY_BILLING_REDIRECT', '/billing/process'),
 
-    /*
-    |--------------------------------------------------------------------------
-    | Billing Capped Amount
-    |--------------------------------------------------------------------------
-    |
-    | The capped price for charging a customer when using the UsageCharge API.
-    |
-    */
-
-    'billing_capped_amount' => env('SHOPIFY_BILLING_CAPPED_AMOUNT'),
-
-    /*
-    |--------------------------------------------------------------------------
-    | Billing Terms
-    |--------------------------------------------------------------------------
-    |
-    | Terms for the usage. Required if using capped amount.
-    |
-    */
-
-    'billing_terms' => env('SHOPIFY_BILLING_TERMS'),
-
     /*
     |--------------------------------------------------------------------------
     | Shopify Webhooks
diff --git a/src/ShopifyApp/resources/database/migrations/2018_08_31_153154_create_plans_table.php b/src/ShopifyApp/resources/database/migrations/2018_08_31_153154_create_plans_table.php
new file mode 100644
index 00000000..ec3e0fd4
--- /dev/null
+++ b/src/ShopifyApp/resources/database/migrations/2018_08_31_153154_create_plans_table.php
@@ -0,0 +1,57 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+class CreatePlansTable extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        Schema::create('plans', function (Blueprint $table) {
+            $table->increments('id');
+
+            // The type of plan, either Plan::CHARGE_RECURRING (1) or Plan::CHARGE_ONETIME (2)
+            $table->integer('type');
+
+            // Name of the plan
+            $table->string('name');
+
+            // Price of the plan
+            $table->decimal('price', 8, 2);
+
+            // Store the amount of the charge, this helps if you are experimenting with pricing
+            $table->decimal('capped_amount', 8, 2)->nullable();
+
+            // Terms for the usage charges
+            $table->string('terms')->nullable();
+
+            // Nullable in case of 0 trial days
+            $table->integer('trial_days')->nullable();
+
+            // Is a test plan or not
+            $table->boolean('test')->default(false);
+
+            // On-install
+            $table->boolean('on_install')->default(false);
+
+            // Provides created_at && updated_at columns
+            $table->timestamps();
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        Schema::drop('plans');
+    }
+}
diff --git a/src/ShopifyApp/resources/database/migrations/2018_08_31_154001_add_plan_to_shops_table_and_charges_table.php b/src/ShopifyApp/resources/database/migrations/2018_08_31_154001_add_plan_to_shops_table_and_charges_table.php
new file mode 100644
index 00000000..dccea642
--- /dev/null
+++ b/src/ShopifyApp/resources/database/migrations/2018_08_31_154001_add_plan_to_shops_table_and_charges_table.php
@@ -0,0 +1,44 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+class AddPlanToShopsTableAndChargesTable extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        Schema::table('charges', function (Blueprint $table) {
+            // Linking
+            $table->integer('plan_id')->unsigned()->nullable();
+            $table->foreign('plan_id')->references('id')->on('plans');
+        });
+
+        Schema::table('shops', function (Blueprint $table) {
+            // Linking
+            $table->integer('plan_id')->unsigned()->nullable();
+            $table->foreign('plan_id')->references('id')->on('plans');
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        Schema::table('charges', function (Blueprint $table) {
+            $table->dropColumn(['plan_id']);
+        });
+
+        Schema::table('shops', function (Blueprint $table) {
+            $table->dropColumn(['plan_id']);
+        });
+    }
+}
diff --git a/src/ShopifyApp/resources/database/migrations/2018_08_31_154502_add_freemium_flag_to_shops_table.php b/src/ShopifyApp/resources/database/migrations/2018_08_31_154502_add_freemium_flag_to_shops_table.php
new file mode 100644
index 00000000..89ac309b
--- /dev/null
+++ b/src/ShopifyApp/resources/database/migrations/2018_08_31_154502_add_freemium_flag_to_shops_table.php
@@ -0,0 +1,32 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+class AddFreemiumFlagToShopsTable extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        Schema::table('shops', function (Blueprint $table) {
+            $table->boolean('freemium')->default(false);
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        Schema::table('shops', function (Blueprint $table) {
+            $table->dropColumn(['freemium']);
+        });
+    }
+}
diff --git a/src/ShopifyApp/resources/database/migrations/2018_09_11_101333_add_usage_charge_support_to_charges_table.php b/src/ShopifyApp/resources/database/migrations/2018_09_11_101333_add_usage_charge_support_to_charges_table.php
new file mode 100644
index 00000000..ede9b655
--- /dev/null
+++ b/src/ShopifyApp/resources/database/migrations/2018_09_11_101333_add_usage_charge_support_to_charges_table.php
@@ -0,0 +1,29 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+class AddUsageChargeSupportToChargesTable extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        Schema::table('charges', function (Blueprint $table) {
+            // Description support
+            $table->string('description')->nullable();
+
+            // Linking to charge_id
+            $table->bigInteger('reference_charge')->nullable();
+        });
+
+        Schema::table('charges', function (Blueprint $table) {
+            // Linking to charge_id, seperate schema block due to contraint issue
+            $table->foreign('reference_charge')->references('charge_id')->on('charges')->onDelete('cascade');
+        });
+    }
+}
diff --git a/src/ShopifyApp/resources/database/migrations/2018_09_12_101645_add_default_to_test_on_charges_table.php b/src/ShopifyApp/resources/database/migrations/2018_09_12_101645_add_default_to_test_on_charges_table.php
new file mode 100644
index 00000000..c3a3214a
--- /dev/null
+++ b/src/ShopifyApp/resources/database/migrations/2018_09_12_101645_add_default_to_test_on_charges_table.php
@@ -0,0 +1,32 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+class AddDefaultToTestOnChargesTable extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        Schema::table('charges', function (Blueprint $table) {
+            $table->boolean('test')->default(false)->change();
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        Schema::table('charges', function (Blueprint $table) {
+            $table->boolean('test')->default(null)->change();
+        });
+    }
+}
diff --git a/src/ShopifyApp/resources/routes.php b/src/ShopifyApp/resources/routes.php
index 6a3a6e7c..330609ee 100644
--- a/src/ShopifyApp/resources/routes.php
+++ b/src/ShopifyApp/resources/routes.php
@@ -67,9 +67,10 @@
     */
 
     Route::get(
-        '/billing',
+        '/billing/{planId?}',
         'OhMyBrew\ShopifyApp\Controllers\BillingController@index'
     )
+    ->where('planId', '^([0-9]+|)$')
     ->name('billing');
 
     /*
@@ -82,10 +83,27 @@
     */
 
     Route::get(
-        '/billing/process',
+        '/billing/process/{planId?}',
         'OhMyBrew\ShopifyApp\Controllers\BillingController@process'
     )
+    ->where('planId', '^([0-9]+|)$')
     ->name('billing.process');
+
+    /*
+    |--------------------------------------------------------------------------
+    | Billing Processor for Usage Charges
+    |--------------------------------------------------------------------------
+    |
+    | Creates a usage charge on a recurring charge.
+    |
+    */
+
+    Route::match(
+        ['get', 'post'],
+        '/billing/usage-charge',
+        'OhMyBrew\ShopifyApp\Controllers\BillingController@usageCharge'
+    )
+    ->name('billing.usage_charge');
 });
 
 Route::group(['middleware' => ['api']], function () {
diff --git a/src/ShopifyApp/resources/views/billing/error.blade.php b/src/ShopifyApp/resources/views/billing/error.blade.php
new file mode 100644
index 00000000..d1fe38f5
--- /dev/null
+++ b/src/ShopifyApp/resources/views/billing/error.blade.php
@@ -0,0 +1,11 @@
+@extends('shopify-app::layouts.error')
+
+@section('content')
+    <div class="flex-center position-ref full-height">
+        <div class="content">
+            <div class="title m-b-md">Oops!</div>
+                <p>{{ $message }}</p>
+            </div>
+        </div>
+    </div>
+@endsection
diff --git a/src/ShopifyApp/resources/views/errors/403.blade.php b/src/ShopifyApp/resources/views/layouts/error.blade.php
similarity index 82%
rename from src/ShopifyApp/resources/views/errors/403.blade.php
rename to src/ShopifyApp/resources/views/layouts/error.blade.php
index 83384844..6e8d3c48 100644
--- a/src/ShopifyApp/resources/views/errors/403.blade.php
+++ b/src/ShopifyApp/resources/views/layouts/error.blade.php
@@ -2,7 +2,7 @@
 <html lang="en">
     <head>
         <meta charset="utf-8">
-        <title>Oops! | 403</title>
+        <title>Oops!</title>
 
         <link href="https://fonts.googleapis.com/css?family=Raleway:100,600" rel="stylesheet" type="text/css">
 
@@ -56,12 +56,7 @@
         <div class="app-wrapper">
             <div class="app-content">
                 <main role="main">
-                    <div class="flex-center position-ref full-height">
-                        <div class="content">
-                            <div class="title m-b-md">Oops!</div>
-                            <p>{{ $exception->getMessage() }}</p>
-                        </div>
-                    </div>
+                    @yield('content')
                 </main>
             </div>
         </div>
diff --git a/tests/Controllers/AuthControllerTest.php b/tests/Controllers/AuthControllerTest.php
index 5da798bf..69a7b98c 100644
--- a/tests/Controllers/AuthControllerTest.php
+++ b/tests/Controllers/AuthControllerTest.php
@@ -19,6 +19,9 @@ public function setUp()
     {
         parent::setUp();
 
+        // Stub in our API class
+        config(['shopify-app.api_class' => new ApiStub()]);
+
         // HMAC for regular tests
         $this->hmac = 'a7448f7c42c9bc025b077ac8b73e7600b6f8012719d21cbeb88db66e5dbbd163';
         $this->hmacParams = [
@@ -36,9 +39,6 @@ public function setUp()
             'code'      => '1234678910',
             'timestamp' => '1337178173',
         ];
-
-        // Stub in our API class
-        config(['shopify-app.api_class' => new ApiStub()]);
     }
 
     public function testLoginTest()
@@ -52,14 +52,18 @@ public function testAuthRedirectsBackToLoginWhenNoShop()
         $response = $this->post('/authenticate');
 
         $response->assertStatus(302);
-        $this->assertEquals('http://localhost/login', $response->headers->get('location'));
+        $response->assertRedirect('http://localhost/login');
     }
 
     public function testAuthRedirectsUserToAuthScreenWhenNoCode()
     {
-        $this->assertEquals(false, config('session.expire_on_close')); // Default for Laravel
+        // Default for Laravel
+        $this->assertNull(config('session.expire_on_close'));
 
+        // Run the request
         $response = $this->post('/authenticate', ['shop' => 'example.myshopify.com']);
+
+        // Check the view
         $response->assertSessionHas('shopify_domain');
         $response->assertViewHas('shopDomain', 'example.myshopify.com');
         $response->assertViewHas(
@@ -67,24 +71,31 @@ public function testAuthRedirectsUserToAuthScreenWhenNoCode()
             'https://example.myshopify.com/admin/oauth/authorize?client_id=&scope=read_products,write_products&redirect_uri=https://localhost/authenticate'
         );
 
-        $this->assertEquals(true, config('session.expire_on_close')); // Override in auth for a single request
+        // Override in auth for a single request
+        $this->assertTrue(config('session.expire_on_close'));
     }
 
     public function testAuthAcceptsShopWithCodeAndUpdatesTokenForShop()
     {
         $response = $this->call('get', '/authenticate', $this->hmacParams);
 
-        $shop = Shop::where('shopify_domain', 'example.myshopify.com')->first();
-        $this->assertEquals('12345678', $shop->shopify_token); // Previous token was 1234
+        // Previous token was 1234
+        $this->assertEquals(
+            '12345678',
+            Shop::where('shopify_domain', 'example.myshopify.com')->first()->shopify_token
+        );
     }
 
     public function testAuthRestoresTrashedShop()
     {
+        // Get the shop, confirm its trashed
         $shop = Shop::withTrashed()->where('shopify_domain', 'trashed-shop.myshopify.com')->first();
         $this->assertTrue($shop->trashed());
 
+        // Do an auth call
         $this->call('get', '/authenticate', $this->hmacTrashedParams);
 
+        // Shop should now be restored
         $shop = $shop->fresh();
         $this->assertFalse($shop->trashed());
     }
@@ -94,11 +105,12 @@ public function testAuthAcceptsShopWithCodeAndRedirectsToHome()
         $response = $this->call('get', '/authenticate', $this->hmacParams);
 
         $response->assertStatus(302);
-        $this->assertEquals('http://localhost', $response->headers->get('location'));
+        $response->assertRedirect('http://localhost');
     }
 
     public function testAuthAcceptsShopWithCodeAndRedirectsToLoginIfRequestIsInvalid()
     {
+        // Make the HMAC invalid
         $params = $this->hmacParams;
         $params['hmac'] = 'MakeMeInvalid';
 
@@ -106,23 +118,27 @@ public function testAuthAcceptsShopWithCodeAndRedirectsToLoginIfRequestIsInvalid
 
         $response->assertSessionHas('error');
         $response->assertStatus(302);
-        $this->assertEquals('http://localhost/login', $response->headers->get('location'));
+        $response->assertRedirect('http://localhost/login');
     }
 
     public function testAuthenticateDoesNotFiresJobsWhenNoConfigForThem()
     {
+        // Fake the queue
         Queue::fake();
 
         $this->call('get', '/authenticate', $this->hmacParams);
 
+        // No jobs should be pushed when theres no config for them
         Queue::assertNotPushed(WebhookInstaller::class);
         Queue::assertNotPushed(ScripttagInstaller::class);
     }
 
     public function testAuthenticateDoesFiresJobs()
     {
+        // Fake the queue
         Queue::fake();
 
+        // Create jobs
         config(['shopify-app.webhooks' => [
             [
                 'topic'   => 'orders/create',
@@ -137,14 +153,17 @@ public function testAuthenticateDoesFiresJobs()
 
         $this->call('get', '/authenticate', $this->hmacParams);
 
+        // Jobs should be called
         Queue::assertPushed(WebhookInstaller::class);
         Queue::assertPushed(ScripttagInstaller::class);
     }
 
     public function testAfterAuthenticateFiresInline()
     {
+        // Fake the queue
         Queue::fake();
 
+        // Create the jobs
         $jobClass = \App\Jobs\AfterAuthenticateJob::class;
         config(['shopify-app.after_authenticate_job' => [
             'job'    => $jobClass,
@@ -155,14 +174,17 @@ public function testAfterAuthenticateFiresInline()
         $method->setAccessible(true);
         $result = $method->invoke(new AuthController());
 
-        $this->assertEquals(true, $result);
+        // Confirm ran, but not pushed
+        $this->assertTrue($result);
         Queue::assertNotPushed($jobClass); // since inline == true
     }
 
     public function testAfterAuthenticateFiresDispatched()
     {
+        // Fake the queue
         Queue::fake();
 
+        // Create the job
         $jobClass = \App\Jobs\AfterAuthenticateJob::class;
         config(['shopify-app.after_authenticate_job' => [
             'job'    => $jobClass,
@@ -173,14 +195,17 @@ public function testAfterAuthenticateFiresDispatched()
         $method->setAccessible(true);
         $result = $method->invoke(new AuthController());
 
-        $this->assertEquals(true, $result);
+        // Confirm ran, and pushed
+        $this->assertTrue($result);
         Queue::assertPushed($jobClass); // since inline == false
     }
 
     public function testAfterAuthenticateDoesNotFireForNoConfig()
     {
+        // Fake the queue
         Queue::fake();
 
+        // Create the jobs... blank
         $jobClass = \App\Jobs\AfterAuthenticateJob::class;
         config(['shopify-app.after_authenticate_job' => []]);
 
@@ -188,7 +213,8 @@ public function testAfterAuthenticateDoesNotFireForNoConfig()
         $method->setAccessible(true);
         $result = $method->invoke(new AuthController());
 
-        $this->assertEquals(false, $result);
+        // Confirm no run, and not pushed
+        $this->assertFalse($result);
         Queue::assertNotPushed($jobClass);
     }
 
@@ -200,11 +226,12 @@ public function testAuthPassesAndRedirectsToReturnUrl()
         $response = $this->call('get', '/authenticate', $this->hmacParams);
 
         $response->assertStatus(302);
-        $this->assertEquals('http://localhost/orders', $response->headers->get('location'));
+        $response->assertRedirect('http://localhost/orders');
     }
 
     public function testReturnToMethod()
     {
+        // Set in AuthShop middleware
         session(['return_to' => 'http://localhost/orders']);
 
         $method = new ReflectionMethod(AuthController::class, 'returnTo');
diff --git a/tests/Controllers/BillingControllerTest.php b/tests/Controllers/BillingControllerTest.php
index b7b5f569..78d1fc29 100644
--- a/tests/Controllers/BillingControllerTest.php
+++ b/tests/Controllers/BillingControllerTest.php
@@ -5,7 +5,9 @@
 use Carbon\Carbon;
 use OhMyBrew\ShopifyApp\Controllers\BillingController;
 use OhMyBrew\ShopifyApp\Models\Charge;
+use OhMyBrew\ShopifyApp\Models\Plan;
 use OhMyBrew\ShopifyApp\Models\Shop;
+use OhMyBrew\ShopifyApp\ShopifyApp;
 use OhMyBrew\ShopifyApp\Test\Stubs\ApiStub;
 use OhMyBrew\ShopifyApp\Test\TestCase;
 use ReflectionMethod;
@@ -19,6 +21,9 @@ public function setUp()
         // Stub in our API class
         config(['shopify-app.api_class' => new ApiStub()]);
 
+        // Create the main class
+        $this->shopifyApp = new ShopifyApp($this->app);
+
         // Base shop for all tests here
         $this->shop = Shop::where('shopify_domain', 'example.myshopify.com')->first();
         session(['shopify_domain' => $this->shop->shopify_domain]);
@@ -43,7 +48,7 @@ public function testShopAcceptsBilling()
         $oldCharge = $shop->charges()->whereIn('type', [Charge::CHARGE_RECURRING, Charge::CHARGE_ONETIME])->orderBy('created_at', 'desc')->first();
 
         // Run with a new charge
-        $response = $this->call('get', '/billing/process', ['charge_id' => $chargeId]);
+        $response = $this->call('get', '/billing/process/1', ['charge_id' => $chargeId]);
 
         // Get the new charge and refresh the old one
         $newCharge = $shop->charges()->get()->last();
@@ -56,115 +61,98 @@ public function testShopAcceptsBilling()
 
     public function testShopDeclinesBilling()
     {
-        $shop = Shop::where('shopify_domain', 'example.myshopify.com')->first();
-        $response = $this->call('get', '/billing/process', ['charge_id' => 10292]);
-        $lastCharge = $shop->charges()->get()->last();
+        // Make the call and grab the last charge
+        $response = $this->call('get', '/billing/process/1', ['charge_id' => 10292]);
+        $lastCharge = $this->shop->charges()->get()->last();
 
-        $response->assertStatus(403);
+        // Should now match
         $this->assertEquals(10292, $lastCharge->charge_id);
         $this->assertEquals('declined', $lastCharge->status);
-        $this->assertEquals(
-            'It seems you have declined the billing charge for this application',
-            $response->exception->getMessage()
-        );
+        $response->assertViewHas('message', 'It seems you have declined the billing charge for this application');
     }
 
-    public function testReturnsBasePlanDetails()
+    public function testReturnOnInstallFlaggedPlan()
     {
         $controller = new BillingController();
-        $method = new ReflectionMethod(BillingController::class, 'planDetails');
+        $method = new ReflectionMethod(BillingController::class, 'getPlan');
         $method->setAccessible(true);
 
         // Based on default config
-        $this->assertEquals(
-            [
-                'name'       => config('shopify-app.billing_plan'),
-                'price'      => config('shopify-app.billing_price'),
-                'test'       => config('shopify-app.billing_test'),
-                'trial_days' => config('shopify-app.billing_trial_days'),
-                'return_url' => url(config('shopify-app.billing_redirect')),
-            ],
-            $method->invoke($controller, $this->shop)
-        );
+        $this->assertEquals(Plan::find(1), $method->invoke($controller, null));
     }
 
-    public function testReturnsBasePlanDetailsWithUsage()
+    public function testReturnPlanPassedToController()
     {
-        config(['shopify-app.billing_capped_amount' => 100.00]);
-        config(['shopify-app.billing_terms' => '$1 for 100 emails.']);
-
         $controller = new BillingController();
-        $method = new ReflectionMethod(BillingController::class, 'planDetails');
+        $method = new ReflectionMethod(BillingController::class, 'getPlan');
         $method->setAccessible(true);
 
         // Based on default config
-        $this->assertEquals(
-            [
-                'name'          => config('shopify-app.billing_plan'),
-                'price'         => config('shopify-app.billing_price'),
-                'test'          => config('shopify-app.billing_test'),
-                'trial_days'    => config('shopify-app.billing_trial_days'),
-                'capped_amount' => config('shopify-app.billing_capped_amount'),
-                'terms'         => config('shopify-app.billing_terms'),
-                'return_url'    => url(config('shopify-app.billing_redirect')),
-            ],
-            $method->invoke($controller, $this->shop)
-        );
+        $this->assertEquals(Plan::find(2), $method->invoke($controller, 2));
     }
 
-    public function testReturnsBasePlanDetailsChangedByCancelledCharge()
+    public function testReturnsLastChargeForShop()
     {
-        $shop = new Shop();
-        $shop->shopify_domain = 'test-cancelled-shop.myshopify.com';
-        $shop->save();
-
-        $charge = new Charge();
-        $charge->charge_id = 267921978;
-        $charge->test = false;
-        $charge->name = 'Base Plan Cancelled';
-        $charge->status = 'cancelled';
-        $charge->type = 1;
-        $charge->price = 25.00;
-        $charge->trial_days = 7;
-        $charge->trial_ends_on = Carbon::today()->addWeeks(1)->format('Y-m-d');
-        $charge->cancelled_on = Carbon::today()->addDays(2)->format('Y-m-d');
-        $charge->shop_id = $shop->id;
-        $charge->save();
-
         $controller = new BillingController();
-        $method = new ReflectionMethod(BillingController::class, 'planDetails');
+        $method = new ReflectionMethod(BillingController::class, 'getLastCharge');
         $method->setAccessible(true);
 
         // Based on default config
-        $this->assertEquals(
-            [
-                'name'       => config('shopify-app.billing_plan'),
-                'price'      => config('shopify-app.billing_price'),
-                'test'       => config('shopify-app.billing_test'),
-                'trial_days' => 5,
-                'return_url' => url(config('shopify-app.billing_redirect')),
-            ],
-            $method->invoke($controller, $shop)
-        );
+        $this->assertInstanceOf(Charge::class, $method->invoke($controller, $this->shop));
     }
 
-    public function testReturnsBaseChargeType()
+    public function testUsageChargeSuccessWithRedirect()
     {
-        $controller = new BillingController();
-        $method = new ReflectionMethod(BillingController::class, 'chargeType');
-        $method->setAccessible(true);
+        // Create a new charge for the shop to make a usage charge against
+        $charge = new Charge();
+        $charge->charge_id = 12939009;
+        $charge->name = 'Base Plan';
+        $charge->type = Charge::CHARGE_RECURRING;
+        $charge->price = 25.00;
+        $charge->shop_id = $this->shop->id;
+        $charge->plan_id = Plan::find(1)->id;
+        $charge->created_at = Carbon::now()->addMinutes(5);
+        $charge->save();
 
-        // Based on default config
-        $this->assertEquals(config('shopify-app.billing_type'), $method->invoke($controller));
+        // Setup the data for the usage charge and the signature for it
+        $data = ['description' => 'One email', 'price' => 1.00, 'redirect' => 'https://localhost/usage-success'];
+        $signature = $this->shopifyApp->createHmac(['data' => $data, 'buildQuery' => true]);
+
+        $response = $this->call('post', '/billing/usage-charge', array_merge($data, ['signature' => $signature]));
+        $lastCharge = $this->shop->charges()->get()->last();
+
+        $response->assertStatus(302);
+        $response->assertRedirect($data['redirect']);
+        $this->assertEquals(Charge::CHARGE_USAGE, $lastCharge->type);
+        $this->assertEquals($data['description'], $lastCharge->description);
+        $this->assertEquals($data['price'], $lastCharge->price);
     }
 
-    public function testReturnsLastChargeForShop()
+    public function testUsageChargeSuccessWithNoRedirect()
     {
-        $controller = new BillingController();
-        $method = new ReflectionMethod(BillingController::class, 'getLastCharge');
-        $method->setAccessible(true);
+        // Create a new charge for the shop to make a usage charge against
+        $charge = new Charge();
+        $charge->charge_id = 21828118;
+        $charge->name = 'Base Plan';
+        $charge->type = Charge::CHARGE_RECURRING;
+        $charge->price = 25.00;
+        $charge->shop_id = $this->shop->id;
+        $charge->plan_id = Plan::find(1)->id;
+        $charge->created_at = Carbon::now()->addMinutes(5);
+        $charge->save();
 
-        // Based on default config
-        $this->assertInstanceOf(Charge::class, $method->invoke($controller, $this->shop));
+        // Setup the data for the usage charge and the signature for it
+        $data = ['description' => 'One email', 'price' => 1.00];
+        $signature = $this->shopifyApp->createHmac(['data' => $data, 'buildQuery' => true]);
+
+        $response = $this->call('post', '/billing/usage-charge', array_merge($data, ['signature' => $signature]));
+        $lastCharge = $this->shop->charges()->get()->last();
+
+        $response->assertStatus(302);
+        $response->assertRedirect('http://localhost');
+        $response->assertSessionHas('success');
+        $this->assertEquals(Charge::CHARGE_USAGE, $lastCharge->type);
+        $this->assertEquals($data['description'], $lastCharge->description);
+        $this->assertEquals($data['price'], $lastCharge->price);
     }
 }
diff --git a/tests/Controllers/HomeControllerTest.php b/tests/Controllers/HomeControllerTest.php
index 89ccd25d..34815577 100644
--- a/tests/Controllers/HomeControllerTest.php
+++ b/tests/Controllers/HomeControllerTest.php
@@ -13,37 +13,43 @@ public function setUp()
 
         // Stub in our API class
         config(['shopify-app.api_class' => new ApiStub()]);
+
+        // Shop for all tests
+        session(['shopify_domain' => 'example.myshopify.com']);
     }
 
     public function testNoShopSessionShouldRedirectToAuthenticate()
     {
+        // Kill the session
+        session()->forget('shopify_domain');
+
         $response = $this->call('get', '/', ['shop' => 'example.myshopify.com']);
-        $this->assertEquals(true, strpos($response->content(), 'Redirecting to http://localhost/authenticate') !== false);
+        $this->assertTrue(strpos($response->content(), 'Redirecting to http://localhost/authenticate') !== false);
     }
 
     public function testWithMismatchedShopsShouldRedirectToAuthenticate()
     {
-        session(['shopify_domain' => 'example.myshopify.com']);
         $response = $this->call('get', '/', ['shop' => 'example-different-shop.myshopify.com']);
-        $this->assertEquals(true, strpos($response->content(), 'Redirecting to http://localhost/authenticate') !== false);
+        $this->assertTrue(strpos($response->content(), 'Redirecting to http://localhost/authenticate') !== false);
     }
 
     public function testShopWithSessionShouldLoad()
     {
-        session(['shopify_domain' => 'example.myshopify.com']);
         $response = $this->get('/');
+
         $response->assertStatus(200);
-        $this->assertEquals(true, strpos($response->content(), "apiKey: ''") !== false);
-        $this->assertEquals(true, strpos($response->content(), "shopOrigin: 'https://example.myshopify.com'") !== false);
+        $this->assertTrue(strpos($response->content(), "apiKey: ''") !== false);
+        $this->assertTrue(strpos($response->content(), "shopOrigin: 'https://example.myshopify.com'") !== false);
     }
 
     public function testShopWithSessionAndDisabledEsdkShouldLoad()
     {
-        session(['shopify_domain' => 'example.myshopify.com']);
+        // Tuen off ESDK
         config(['shopify-app.esdk_enabled' => false]);
 
         $response = $this->get('/');
+
         $response->assertStatus(200);
-        $this->assertEquals(false, strpos($response->content(), 'ShopifyApp.init'));
+        $this->assertFalse(strpos($response->content(), 'ShopifyApp.init'));
     }
 }
diff --git a/tests/Controllers/WebhookControllerTest.php b/tests/Controllers/WebhookControllerTest.php
index 049bc03d..ccd587cd 100644
--- a/tests/Controllers/WebhookControllerTest.php
+++ b/tests/Controllers/WebhookControllerTest.php
@@ -15,6 +15,7 @@ public function setUp()
     {
         parent::setUp();
 
+        // Mock headers that match Shopify
         $this->headers = [
             'HTTP_CONTENT_TYPE'          => 'application/json',
             'HTTP_X_SHOPIFY_SHOP_DOMAIN' => 'example.myshopify.com',
@@ -24,8 +25,10 @@ public function setUp()
 
     public function testShouldReturn201ResponseOnSuccess()
     {
+        // Fake the queue
         Queue::fake();
 
+        // Create a webhook call and pass in our own headers and data
         $response = $this->call(
             'post',
             '/webhook/orders-create',
@@ -35,13 +38,15 @@ public function testShouldReturn201ResponseOnSuccess()
             $this->headers,
             file_get_contents(__DIR__.'/../fixtures/webhook.json')
         );
-        $response->assertStatus(201);
 
+        // Check it was created and job was pushed
+        $response->assertStatus(201);
         Queue::assertPushed(\App\Jobs\OrdersCreateJob::class);
     }
 
     public function testShouldReturnErrorResponseOnFailure()
     {
+        // Create a webhook call and pass in our own headers and data
         $response = $this->call(
             'post',
             '/webhook/products-create',
@@ -51,6 +56,8 @@ public function testShouldReturnErrorResponseOnFailure()
             $this->headers,
             file_get_contents(__DIR__.'/../fixtures/webhook.json')
         );
+
+        // Check it contains error and exception matches
         $response->assertStatus(500);
         $this->assertEquals('Missing webhook job: \App\Jobs\ProductsCreateJob', $response->exception->getMessage());
     }
@@ -61,12 +68,14 @@ public function testShouldCaseTypeToClass()
         $method = new ReflectionMethod(WebhookController::class, 'getJobClassFromType');
         $method->setAccessible(true);
 
+        // Map URL path to job
         $types = [
             'orders-create'     => 'OrdersCreateJob',
             'super-duper-order' => 'SuperDuperOrderJob',
             'order'             => 'OrderJob',
         ];
 
+        // Confirm mapping
         foreach ($types as $type => $className) {
             $this->assertEquals("\\App\\Jobs\\$className", $method->invoke($controller, $type));
         }
@@ -74,8 +83,10 @@ public function testShouldCaseTypeToClass()
 
     public function testWebhookShouldRecieveData()
     {
+        // Fake the queue
         Queue::fake();
 
+        // Create a webhook call and pass in our own headers and data
         $response = $this->call(
             'post',
             '/webhook/orders-create',
@@ -85,8 +96,9 @@ public function testWebhookShouldRecieveData()
             $this->headers,
             file_get_contents(__DIR__.'/../fixtures/webhook.json')
         );
-        $response->assertStatus(201);
 
+        // Check it was created, and job was ushed with matching data from fixture
+        $response->assertStatus(201);
         Queue::assertPushed(\App\Jobs\OrdersCreateJob::class, function ($job) {
             return $job->shopDomain === 'example.myshopify.com'
                    && $job->data instanceof \stdClass
diff --git a/tests/Jobs/AppUninstalledJobTest.php b/tests/Jobs/AppUninstalledJobTest.php
index 4d764394..41e129a1 100644
--- a/tests/Jobs/AppUninstalledJobTest.php
+++ b/tests/Jobs/AppUninstalledJobTest.php
@@ -20,6 +20,7 @@ public function setup()
         $this->shop->shopify_domain = 'example-isolated.myshopify.com';
         $this->shop->save();
 
+        // Get the data
         $this->data = json_decode(file_get_contents(__DIR__.'/../fixtures/app_uninstalled.json'));
     }
 
@@ -84,6 +85,6 @@ public function testJobSoftDeletesShopAndCharges()
     public function testJobDoesNothingForUnknownShop()
     {
         $job = new AppUninstalledJob('unknown-shop.myshopify.com', null);
-        $this->assertEquals(false, $job->handle());
+        $this->assertFalse($job->handle());
     }
 }
diff --git a/tests/Libraries/BillingPlanTest.php b/tests/Libraries/BillingPlanTest.php
index 9bfd4257..df2f90d9 100644
--- a/tests/Libraries/BillingPlanTest.php
+++ b/tests/Libraries/BillingPlanTest.php
@@ -3,6 +3,7 @@
 namespace OhMyBrew\ShopifyApp\Test\Libraries;
 
 use OhMyBrew\ShopifyApp\Libraries\BillingPlan;
+use OhMyBrew\ShopifyApp\Models\Plan;
 use OhMyBrew\ShopifyApp\Models\Shop;
 use OhMyBrew\ShopifyApp\Test\Stubs\ApiStub;
 use OhMyBrew\ShopifyApp\Test\TestCase;
@@ -16,54 +17,55 @@ public function setUp()
         // Stub in our API class
         config(['shopify-app.api_class' => new ApiStub()]);
 
-        // Base shop and plan
+        // Base shop to use
         $this->shop = Shop::find(1);
-        $this->plan = [
-            'name'       => 'Basic Plan',
-            'price'      => 3.00,
-            'trial_days' => 0,
-            'return_url' => 'http://example.com/',
-        ];
     }
 
     public function testShouldReturnConfirmationUrl()
     {
-        $url = (new BillingPlan($this->shop))->setDetails($this->plan)->getConfirmationUrl();
-
         $this->assertEquals(
             'https://example.myshopify.com/admin/charges/1029266947/confirm_recurring_application_charge?signature=BAhpBANeWT0%3D--64de8739eb1e63a8f848382bb757b20343eb414f',
-            $url
+            (new BillingPlan($this->shop, Plan::find(1)))->getConfirmationUrl()
         );
     }
 
     public function testShouldReturnConfirmationUrlWhenUsageIsEnabled()
     {
-        $plan = array_merge($this->plan, [
-            'capped_amount' => 100.00,
-            'terms'         => '$1 for 500 emails',
-        ]);
-        $url = (new BillingPlan($this->shop))->setDetails($plan)->getConfirmationUrl();
-
         $this->assertEquals(
-            'https://example.myshopify.com/admin/charges/1029266947/confirm_recurring_application_charge?signature=BAhpBANeWT0%3D--64de8739eb1e63a8f848382bb757b20343eb414f',
-            $url
+            'https://example.myshopify.com/admin/charges/1017262355/confirm_application_charge?signature=BAhpBBMxojw%3D--1139a82a3433b1a6771786e03f02300440e11883',
+            (new BillingPlan($this->shop, Plan::find(3)))->getConfirmationUrl()
         );
     }
 
     /**
-     * @expectedException \Exception
-     * @expectedExceptionMessage Plan details are missing for confirmation URL request.
+     * @expectedException \ArgumentCountError
      */
-    public function testShouldNotReturnConfirmationUrlAndThrowException()
+    public function testShouldThrowExceptionForMissingPlan()
     {
-        (new BillingPlan($this->shop))->getConfirmationUrl();
+        new BillingPlan($this->shop);
+    }
+
+    public function testShouldReturnChargeParams()
+    {
+        $this->assertEquals(
+            [
+                'test'          => false,
+                'trial_days'    => '7',
+                'name'          => 'Capped Plan',
+                'price'         => '5',
+                'return_url'    => secure_url(config('shopify-app.billing_redirect'), ['plan_id' => 4]),
+                'capped_amount' => '100',
+                'terms'         => '$1 for 500 emails',
+            ],
+            (new BillingPlan($this->shop, Plan::find(4)))->getChargeParams()
+        );
     }
 
     public function testShouldActivatePlan()
     {
-        $response = (new BillingPlan($this->shop))->setChargeId(1029266947)->activate();
+        $response = (new BillingPlan($this->shop, Plan::find(1)))->setChargeId(1029266947)->activate();
 
-        $this->assertEquals(true, is_object($response));
+        $this->assertTrue(is_object($response));
         $this->assertEquals('active', $response->status);
     }
 
@@ -73,14 +75,14 @@ public function testShouldActivatePlan()
      */
     public function testShouldNotActivatePlanAndThrowException()
     {
-        (new BillingPlan($this->shop))->activate();
+        (new BillingPlan($this->shop, Plan::find(1)))->activate();
     }
 
     public function testShouldGetChargeDetails()
     {
-        $response = (new BillingPlan($this->shop))->setChargeId(1029266947)->getCharge();
+        $response = (new BillingPlan($this->shop, Plan::find(1)))->setChargeId(1029266947)->getCharge();
 
-        $this->assertEquals(true, is_object($response));
+        $this->assertTrue(is_object($response));
         $this->assertEquals('accepted', $response->status);
     }
 
@@ -90,6 +92,6 @@ public function testShouldGetChargeDetails()
      */
     public function testShouldNotGetChargeDetailsAndThrowException()
     {
-        (new BillingPlan($this->shop))->getCharge();
+        (new BillingPlan($this->shop, Plan::find(1)))->getCharge();
     }
 }
diff --git a/tests/Middleware/AuthProxyMiddlewareTest.php b/tests/Middleware/AuthProxyMiddlewareTest.php
index f275a3f1..036dd36a 100644
--- a/tests/Middleware/AuthProxyMiddlewareTest.php
+++ b/tests/Middleware/AuthProxyMiddlewareTest.php
@@ -32,6 +32,7 @@ public function setUp()
      */
     public function testDenysForMissingShop()
     {
+        // Remove shop from params
         $query = $this->queryParams;
         unset($query['shop']);
         Input::merge($query);
@@ -42,7 +43,7 @@ public function testDenysForMissingShop()
             $called = true;
         });
 
-        $this->assertEquals(false, $called);
+        $this->assertFalse($called);
     }
 
     public function testRuns()
@@ -50,7 +51,7 @@ public function testRuns()
         Input::merge($this->queryParams);
 
         // Confirm no shop
-        $this->assertEquals(null, session('shopify_domain'));
+        $this->assertNull(session('shopify_domain'));
 
         $called = false;
         (new AuthProxy())->handle(request(), function ($request) use (&$called) {
@@ -66,7 +67,7 @@ public function testRuns()
         });
 
         // Confirm full run
-        $this->assertEquals(true, $called);
+        $this->assertTrue($called);
     }
 
     /**
@@ -75,6 +76,7 @@ public function testRuns()
      */
     public function testDoesNotRunForInvalidSignature()
     {
+        // Make the signature invalid
         $query = $this->queryParams;
         $query['oops'] = 'i-did-it-again';
         Input::merge($query);
@@ -85,6 +87,6 @@ public function testDoesNotRunForInvalidSignature()
             $called = true;
         });
 
-        $this->assertEquals(false, $called);
+        $this->assertFalse($called);
     }
 }
diff --git a/tests/Middleware/AuthShopMiddlewareTest.php b/tests/Middleware/AuthShopMiddlewareTest.php
index 25b7daea..67adfe05 100644
--- a/tests/Middleware/AuthShopMiddlewareTest.php
+++ b/tests/Middleware/AuthShopMiddlewareTest.php
@@ -17,7 +17,7 @@ public function testShopHasNoAccessShouldAbort()
         });
 
         $this->assertFalse($called);
-        $this->assertEquals(true, strpos($result, 'Redirecting to http://localhost/authenticate') !== false);
+        $this->assertTrue(strpos($result, 'Redirecting to http://localhost/authenticate') !== false);
     }
 
     public function testShopHasWithAccessShouldPassMiddleware()
@@ -31,7 +31,7 @@ public function testShopHasWithAccessShouldPassMiddleware()
             $called = true;
         });
 
-        $this->assertEquals(true, $called);
+        $this->assertTrue($called);
     }
 
     public function testShopWithNoTokenShouldNotPassMiddleware()
@@ -46,7 +46,7 @@ public function testShopWithNoTokenShouldNotPassMiddleware()
         });
 
         $this->assertFalse($called);
-        $this->assertEquals(true, strpos($result, 'Redirecting to http://localhost/authenticate') !== false);
+        $this->assertTrue(strpos($result, 'Redirecting to http://localhost/authenticate') !== false);
     }
 
     public function testShopTrashedShouldNotPassMiddleware()
@@ -61,7 +61,7 @@ public function testShopTrashedShouldNotPassMiddleware()
         });
 
         $this->assertFalse($called);
-        $this->assertEquals(true, strpos($result, 'Redirecting to http://localhost/authenticate') !== false);
+        $this->assertTrue(strpos($result, 'Redirecting to http://localhost/authenticate') !== false);
     }
 
     public function testShopsWhichDoNotMatchShouldKillSessionAndDirectToReAuthenticate()
@@ -129,6 +129,6 @@ public function testShouldSaveReturnUrl()
 
         $this->assertFalse($called);
         $this->assertEquals('http://localhost/orders', session('return_to'));
-        $this->assertEquals(true, strpos($result, 'Redirecting to http://localhost/authenticate') !== false);
+        $this->assertTrue(strpos($result, 'Redirecting to http://localhost/authenticate') !== false);
     }
 }
diff --git a/tests/Middleware/AuthWebhookMiddlewareTest.php b/tests/Middleware/AuthWebhookMiddlewareTest.php
index e8fab081..efa00f7c 100644
--- a/tests/Middleware/AuthWebhookMiddlewareTest.php
+++ b/tests/Middleware/AuthWebhookMiddlewareTest.php
@@ -30,13 +30,16 @@ public function testDenysForMissingHmacHeader()
     {
         request()->header('x-shopify-shop-domain', 'example.myshopify.com');
         (new AuthWebhook())->handle(request(), function ($request) {
+            // ...
         });
     }
 
     public function testRuns()
     {
+        // Fake the queue
         Queue::fake();
 
+        // Run the call with our owm mocked Shopify headers and data
         $response = $this->call(
             'post',
             '/webhook/orders-create',
@@ -50,13 +53,16 @@ public function testRuns()
             ],
             file_get_contents(__DIR__.'/../fixtures/webhook.json')
         );
+
         $response->assertStatus(201);
     }
 
     public function testInvalidHmacWontRun()
     {
+        // Fake the data
         Queue::fake();
 
+        // Run the call with our owm mocked Shopify headers and data
         $response = $this->call(
             'post',
             '/webhook/orders-create',
@@ -70,6 +76,7 @@ public function testInvalidHmacWontRun()
             ],
             file_get_contents(__DIR__.'/../fixtures/webhook.json').'invalid'
         );
+
         $response->assertStatus(401);
     }
 }
diff --git a/tests/Middleware/BillableMiddlewareTest.php b/tests/Middleware/BillableMiddlewareTest.php
index d723eb0d..892025d9 100644
--- a/tests/Middleware/BillableMiddlewareTest.php
+++ b/tests/Middleware/BillableMiddlewareTest.php
@@ -20,30 +20,29 @@ public function testEnabledBillingWithUnpaidShop()
         });
 
         $this->assertFalse($called);
-        $this->assertEquals(true, strpos($result, 'Redirecting to http://localhost/billing') !== false);
+        $this->assertTrue(strpos($result, 'Redirecting to http://localhost/billing') !== false);
     }
 
-    public function testEnabledBillingWithShopWhoDeclinedCharges()
+    public function testEnabledBillingWithPaidShop()
     {
         // Enable billing and set a shop
         config(['shopify-app.billing_enabled' => true]);
-        session(['shopify_domain' => 'trashed-shop.myshopify.com']);
+        session(['shopify_domain' => 'example.myshopify.com']);
 
         $called = false;
         $result = (new Billable())->handle(request(), function ($request) use (&$called) {
-            // Should never be called
+            // Should be called
             $called = true;
         });
 
-        $this->assertFalse($called);
-        $this->assertEquals(true, strpos($result, 'Redirecting to http://localhost/billing') !== false);
+        $this->assertTrue($called);
     }
 
-    public function testEnabledBillingWithPaidShop()
+    public function testEnabledBillingWithGrandfatheredShop()
     {
         // Enable billing and set a shop
         config(['shopify-app.billing_enabled' => true]);
-        session(['shopify_domain' => 'example.myshopify.com']);
+        session(['shopify_domain' => 'grandfathered.myshopify.com']);
 
         $called = false;
         $result = (new Billable())->handle(request(), function ($request) use (&$called) {
@@ -54,11 +53,11 @@ public function testEnabledBillingWithPaidShop()
         $this->assertTrue($called);
     }
 
-    public function testEnabledBillingWithGrandfatheredShop()
+    public function testEnabledBillingWithFreemiumShop()
     {
         // Enable billing and set a shop
         config(['shopify-app.billing_enabled' => true]);
-        session(['shopify_domain' => 'grandfathered.myshopify.com']);
+        session(['shopify_domain' => 'freemium-shop.myshopify.com']);
 
         $called = false;
         $result = (new Billable())->handle(request(), function ($request) use (&$called) {
diff --git a/tests/Models/ChargeModelTest.php b/tests/Models/ChargeModelTest.php
index 58602e85..157f8955 100644
--- a/tests/Models/ChargeModelTest.php
+++ b/tests/Models/ChargeModelTest.php
@@ -3,6 +3,7 @@
 namespace OhMyBrew\ShopifyApp\Test\Models;
 
 use OhMyBrew\ShopifyApp\Models\Charge;
+use OhMyBrew\ShopifyApp\Models\Plan;
 use OhMyBrew\ShopifyApp\Models\Shop;
 use OhMyBrew\ShopifyApp\Test\Stubs\ApiStub;
 use OhMyBrew\ShopifyApp\Test\TestCase;
@@ -11,23 +12,22 @@ class ChargeModelTest extends TestCase
 {
     public function testBelongsToShop()
     {
-        $this->assertInstanceOf(
-            Shop::class,
-            Charge::find(1)->shop
-        );
+        $this->assertInstanceOf(Shop::class, Charge::find(1)->shop);
     }
 
     public function testChargeImplementsType()
     {
-        $this->assertEquals(
-            Charge::CHARGE_RECURRING,
-            Charge::find(1)->type
-        );
+        $this->assertEquals(Charge::CHARGE_RECURRING, Charge::find(1)->type);
+    }
+
+    public function testBelongsToPlan()
+    {
+        $this->assertInstanceOf(Plan::class, Charge::find(1)->plan);
     }
 
     public function testIsTest()
     {
-        $this->assertEquals(true, Charge::find(1)->isTest());
+        $this->assertTrue(Charge::find(1)->isTest());
     }
 
     public function testIsType()
diff --git a/tests/Models/PlanModelTest.php b/tests/Models/PlanModelTest.php
new file mode 100644
index 00000000..673688d4
--- /dev/null
+++ b/tests/Models/PlanModelTest.php
@@ -0,0 +1,44 @@
+<?php
+
+namespace OhMyBrew\ShopifyApp\Test\Models;
+
+use Illuminate\Database\Eloquent\Collection;
+use OhMyBrew\ShopifyApp\Models\Plan;
+use OhMyBrew\ShopifyApp\Test\TestCase;
+
+class PlanModelTest extends TestCase
+{
+    public function testReturnsChargesForPlan()
+    {
+        $charges = Plan::find(1)->charges;
+
+        $this->assertInstanceOf(Collection::class, $charges);
+        $this->assertTrue(count($charges) > 0);
+    }
+
+    public function testReturnsTypeAsString()
+    {
+        $plan = Plan::find(1);
+
+        $this->assertEquals('recurring_application_charge', $plan->typeAsString());
+        $this->assertEquals('recurring_application_charges', $plan->typeAsString(true));
+    }
+
+    public function testPlanHasTrial()
+    {
+        $this->assertFalse(Plan::find(2)->hasTrial());
+        $this->assertTrue(Plan::find(1)->hasTrial());
+    }
+
+    public function testPlanOnInstallFlag()
+    {
+        $this->assertFalse(Plan::find(2)->isOnInstall());
+        $this->assertTrue(Plan::find(1)->isOnInstall());
+    }
+
+    public function testPlanIsTest()
+    {
+        $this->assertTrue(Plan::find(3)->isTest());
+        $this->assertFalse(Plan::find(1)->isTest());
+    }
+}
diff --git a/tests/Models/ShopModelTest.php b/tests/Models/ShopModelTest.php
index 40ad1282..203d938e 100644
--- a/tests/Models/ShopModelTest.php
+++ b/tests/Models/ShopModelTest.php
@@ -2,6 +2,7 @@
 
 namespace OhMyBrew\ShopifyApp\Test\Models;
 
+use OhMyBrew\ShopifyApp\Models\Plan;
 use OhMyBrew\ShopifyApp\Models\Shop;
 use OhMyBrew\ShopifyApp\Test\TestCase;
 
@@ -49,8 +50,8 @@ public function testShopShouldReturnGrandfatheredState()
         $shop = Shop::where('shopify_domain', 'grandfathered.myshopify.com')->first();
         $shop_2 = Shop::where('shopify_domain', 'example.myshopify.com')->first();
 
-        $this->assertEquals(true, $shop->isGrandfathered());
-        $this->assertEquals(false, $shop_2->isGrandfathered());
+        $this->assertTrue($shop->isGrandfathered());
+        $this->assertFalse($shop_2->isGrandfathered());
     }
 
     public function testShopCanSoftDeleteAndBeRestored()
@@ -77,7 +78,23 @@ public function testShouldReturnBoolForChargesApplied()
         $shop = Shop::where('shopify_domain', 'grandfathered.myshopify.com')->first();
         $shop_2 = Shop::where('shopify_domain', 'example.myshopify.com')->first();
 
-        $this->assertEquals(false, $shop->hasCharges());
-        $this->assertEquals(true, $shop_2->hasCharges());
+        $this->assertFalse($shop->hasCharges());
+        $this->assertTrue($shop_2->hasCharges());
+    }
+
+    public function testShopReturnsPlan()
+    {
+        $this->assertInstanceOf(Plan::class, Shop::find(1)->plan);
+    }
+
+    public function testShopReturnsNoPlan()
+    {
+        $this->assertEquals(null, Shop::find(5)->plan);
+    }
+
+    public function testShopIsFreemiumAndNotFreemium()
+    {
+        $this->assertTrue(Shop::find(5)->isFreemium());
+        $this->assertFalse(Shop::find(1)->isFreemium());
     }
 }
diff --git a/tests/Observers/ShopObserverTest.php b/tests/Observers/ShopObserverTest.php
index f81d2edc..2d523e73 100644
--- a/tests/Observers/ShopObserverTest.php
+++ b/tests/Observers/ShopObserverTest.php
@@ -19,4 +19,15 @@ public function testObserverAddsNamespace()
 
         $this->assertEquals('shopify-test-namespace', $shop->namespace);
     }
+
+    public function testObserverSetsFreemiumFlag()
+    {
+        config(['shopify-app.billing_freemium_enabled' => true]);
+
+        $shop = new Shop();
+        $shop->shopify_domain = 'observer-freemium.myshopify.com';
+        $shop->save();
+
+        $this->assertTrue($shop->isFreemium());
+    }
 }
diff --git a/tests/ShopifyAppTest.php b/tests/ShopifyAppTest.php
index aaaee770..039d32b6 100644
--- a/tests/ShopifyAppTest.php
+++ b/tests/ShopifyAppTest.php
@@ -36,7 +36,8 @@ public function testShopWithSession()
     public function testCreatesNewShopWithSessionIfItDoesNotExist()
     {
         session(['shopify_domain' => 'example-nonexistant.myshopify.com']);
-        $this->assertEquals(null, Shop::where('shopify_domain', 'example-nonexistant.myshopify.com')->first());
+
+        $this->assertNull(Shop::where('shopify_domain', 'example-nonexistant.myshopify.com')->first());
 
         $this->shopifyApp->shop();
 
@@ -67,7 +68,7 @@ public function testShopSanitize()
 
         // Test for empty shops
         foreach ($domains_3 as $domain) {
-            $this->assertEquals(null, $this->shopifyApp->sanitizeShopDomain($domain));
+            $this->assertNull($this->shopifyApp->sanitizeShopDomain($domain));
         }
     }
 
@@ -76,7 +77,8 @@ public function testShouldUseDefaultModel()
         session(['shopify_domain' => 'example.myshopify.com']);
 
         $shop = $this->shopifyApp->shop();
-        $this->assertEquals('OhMyBrew\ShopifyApp\Models\Shop', get_class($shop));
+
+        $this->assertEquals(\OhMyBrew\ShopifyApp\Models\Shop::class, get_class($shop));
     }
 
     public function testShouldAllowForModelOverride()
@@ -85,7 +87,36 @@ public function testShouldAllowForModelOverride()
         config(['shopify-app.shop_model' => 'OhMyBrew\ShopifyApp\Test\Stubs\ShopModelStub']);
 
         $shop = $this->shopifyApp->shop();
-        $this->assertEquals('OhMyBrew\ShopifyApp\Test\Stubs\ShopModelStub', get_class($shop));
+
+        $this->assertEquals(\OhMyBrew\ShopifyApp\Test\Stubs\ShopModelStub::class, get_class($shop));
         $this->assertEquals('hello', $shop->hello());
     }
+
+    public function testHmacCreator()
+    {
+        // Set the secret to use for HMAC creations
+        $secret = 'hello';
+        config(['shopify-app.api_secret' => $secret]);
+
+        // Raw data
+        $data = 'one-two-three';
+        $this->assertEquals(
+            hash_hmac('sha256', $data, $secret, true),
+            $this->shopifyApp->createHmac(['data' => $data, 'raw' => true])
+        );
+
+        // Raw data encoded
+        $data = 'one-two-three';
+        $this->assertEquals(
+            base64_encode(hash_hmac('sha256', $data, $secret, true)),
+            $this->shopifyApp->createHmac(['data' => $data, 'raw' => true, 'encode' => true])
+        );
+
+        // Query build (sorts array and builds query string)
+        $data = ['one' => 1, 'two' => 2, 'three' => 3];
+        $this->assertEquals(
+            hash_hmac('sha256', 'one=1three=3two=2', $secret, false),
+            $this->shopifyApp->createHmac(['data' => $data, 'buildQuery' => true])
+        );
+    }
 }
diff --git a/tests/TestCase.php b/tests/TestCase.php
index 8a622508..976d54f3 100644
--- a/tests/TestCase.php
+++ b/tests/TestCase.php
@@ -4,6 +4,7 @@
 
 use Carbon\Carbon;
 use OhMyBrew\ShopifyApp\Models\Charge;
+use OhMyBrew\ShopifyApp\Models\Plan;
 use OhMyBrew\ShopifyApp\Models\Shop;
 use OhMyBrew\ShopifyApp\ShopifyAppProvider;
 use Orchestra\Database\ConsoleServiceProvider;
@@ -62,6 +63,7 @@ protected function setupDatabase($app)
 
     protected function seedDatabase()
     {
+        $this->createPlans();
         $this->createShops();
         $this->createCharges();
     }
@@ -73,6 +75,7 @@ protected function createShops()
             [
                 'shopify_domain' => 'example.myshopify.com',
                 'shopify_token'  => '1234',
+                'plan_id'        => 1,
             ],
 
             // Non-paid shop, grandfathered
@@ -92,6 +95,12 @@ protected function createShops()
             [
                 'shopify_domain' => 'no-token-shop.myshopify.com',
             ],
+
+            // Shop on freemium
+            [
+                'shopify_domain' => 'freemium-shop.myshopify.com',
+                'freemium'       => true,
+            ],
         ];
 
         // Build the shops
@@ -124,6 +133,7 @@ public function createCharges()
                 'trial_days'    => 7,
                 'trial_ends_on' => Carbon::createFromDate(2018, 6, 3, 'UTC')->addWeeks(1)->format('Y-m-d'),
                 'shop_id'       => Shop::where('shopify_domain', 'example.myshopify.com')->first()->id,
+                'plan_id'       => 1,
             ],
 
             // Test = false, status = active, trial = 7, active trial = yes
@@ -137,6 +147,7 @@ public function createCharges()
                 'trial_days'    => 7,
                 'trial_ends_on' => Carbon::today()->addDays(2)->format('Y-m-d'),
                 'shop_id'       => Shop::where('shopify_domain', 'example.myshopify.com')->first()->id,
+                'plan_id'       => 1,
             ],
 
             // Test = false, status = active, trial = 7, active trial = no
@@ -150,6 +161,7 @@ public function createCharges()
                 'trial_days'    => 7,
                 'trial_ends_on' => Carbon::today()->subWeeks(4)->format('Y-m-d'),
                 'shop_id'       => Shop::where('shopify_domain', 'example.myshopify.com')->first()->id,
+                'plan_id'       => 1,
             ],
 
             // Test = false, status = active, trial = 0
@@ -162,6 +174,7 @@ public function createCharges()
                 'price'      => 25.00,
                 'trial_days' => 0,
                 'shop_id'    => Shop::where('shopify_domain', 'example.myshopify.com')->first()->id,
+                'plan_id'    => 2,
             ],
 
             // Test = false, status = declined, trial = 7, active trial = true
@@ -173,6 +186,7 @@ public function createCharges()
                 'type'      => 1,
                 'price'     => 25.00,
                 'shop_id'   => Shop::where('shopify_domain', 'no-token-shop.myshopify.com')->first()->id,
+                'plan_id'   => 1,
             ],
 
             // Test = false, status = cancelled
@@ -185,6 +199,7 @@ public function createCharges()
                 'price'        => 25.00,
                 'shop_id'      => Shop::where('shopify_domain', 'example.myshopify.com')->first()->id,
                 'cancelled_on' => Carbon::today()->format('Y-m-d'),
+                'plan_id'      => 1,
             ],
 
             // Test = false, status = cancelled, trial = 7
@@ -199,6 +214,7 @@ public function createCharges()
                 'trial_ends_on' => Carbon::today()->addWeeks(1)->format('Y-m-d'),
                 'cancelled_on'  => Carbon::today()->addDays(2)->format('Y-m-d'),
                 'shop_id'       => Shop::withTrashed()->where('shopify_domain', 'trashed-shop.myshopify.com')->first()->id,
+                'plan_id'       => 1,
             ],
         ];
 
@@ -211,4 +227,60 @@ public function createCharges()
             $charge->save();
         }
     }
+
+    public function createPlans()
+    {
+        $plans = [
+            // Basic Plan with Trial
+            [
+                'type'       => 1,
+                'name'       => 'Basic Plan with Trial',
+                'price'      => 5.00,
+                'trial_days' => 7,
+                'test'       => false,
+                'on_install' => true,
+            ],
+
+            // Basic Plan with No Trial
+            [
+                'type'       => 1,
+                'name'       => 'Basic Plan with No Trial',
+                'price'      => 5.00,
+                'trial_days' => 0,
+                'test'       => false,
+                'on_install' => false,
+            ],
+
+            // Test Plan
+            [
+                'type'       => 2,
+                'name'       => 'Test Plan',
+                'price'      => 5.00,
+                'trial_days' => 7,
+                'test'       => true,
+                'on_install' => false,
+            ],
+
+            // Test Plan
+            [
+                'type'          => 1,
+                'name'          => 'Capped Plan',
+                'price'         => 5.00,
+                'trial_days'    => 7,
+                'test'          => false,
+                'on_install'    => false,
+                'capped_amount' => 100.00,
+                'terms'         => '$1 for 500 emails',
+            ],
+        ];
+
+        // Build the plans
+        foreach ($plans as $planData) {
+            $plan = new Plan();
+            foreach ($planData as $key => $value) {
+                $plan->{$key} = $value;
+            }
+            $plan->save();
+        }
+    }
 }
diff --git a/tests/fixtures/14fac79628dbb02150f6bbb072a31620fcc5b445.json b/tests/fixtures/14fac79628dbb02150f6bbb072a31620fcc5b445.json
new file mode 100644
index 00000000..cc0390f5
--- /dev/null
+++ b/tests/fixtures/14fac79628dbb02150f6bbb072a31620fcc5b445.json
@@ -0,0 +1,12 @@
+{
+    "usage_charge": {
+        "id": 1034618208,
+        "description": "One email",
+        "price": "1.00",
+        "created_at": "2018-07-05T13:05:43-04:00",
+        "billing_on": "2018-08-04",
+        "balance_used": 11.0,
+        "balance_remaining": 89.0,
+        "risk_level": 0.08
+    }
+}
\ No newline at end of file
diff --git a/tests/fixtures/9aeb4b1bdd9bc97203c63c008e766f55e9af3a39.json b/tests/fixtures/9aeb4b1bdd9bc97203c63c008e766f55e9af3a39.json
new file mode 100644
index 00000000..9191cb45
--- /dev/null
+++ b/tests/fixtures/9aeb4b1bdd9bc97203c63c008e766f55e9af3a39.json
@@ -0,0 +1,16 @@
+{
+    "application_charge": {
+        "id": 1017262355,
+        "name": "Basic Plan",
+        "api_client_id": 755357713,
+        "price": "5.00",
+        "status": "pending",
+        "return_url": "http://super-duper.shopifyapps.com/",
+        "test": null,
+        "created_at": "2018-07-05T13:11:28-04:00",
+        "updated_at": "2018-07-05T13:11:28-04:00",
+        "charge_type": null,
+        "decorated_return_url": "http://example.shopifyapps.com/?charge_id=1017262355",
+        "confirmation_url": "https://example.myshopify.com/admin/charges/1017262355/confirm_application_charge?signature=BAhpBBMxojw%3D--1139a82a3433b1a6771786e03f02300440e11883"
+    }
+}
\ No newline at end of file
diff --git a/tests/fixtures/c9703dd31785be2b8f0a1a4c5916090542b6e11b.json b/tests/fixtures/c9703dd31785be2b8f0a1a4c5916090542b6e11b.json
new file mode 100644
index 00000000..cc0390f5
--- /dev/null
+++ b/tests/fixtures/c9703dd31785be2b8f0a1a4c5916090542b6e11b.json
@@ -0,0 +1,12 @@
+{
+    "usage_charge": {
+        "id": 1034618208,
+        "description": "One email",
+        "price": "1.00",
+        "created_at": "2018-07-05T13:05:43-04:00",
+        "billing_on": "2018-08-04",
+        "balance_used": 11.0,
+        "balance_remaining": 89.0,
+        "risk_level": 0.08
+    }
+}
\ No newline at end of file