This is a simple example project that makes use of the update_settings_bundle action.
First build and run the sample project on a simulator or device. It should show you the current version and build number: 1.0.0 (1). This information is taken from the app's Info.plist.
Tap the version number to view the settings for SettingsBundleExample in the Settings app. You'll see the same version and build number as well as a blank field for the Build date.
Now run Fastlane:
bundle install
bundle exec fastlane testRun the sample app again. It should display 1.0.0 (2). Tap the version number again to see the update to the settings bundle. The Build date field should show the current date.