Updating an already packaged app

[ndonkoHenri]

Let's consider for instance I make a desktop app for a client and plan to update weekly: how can update this app found on my client's computer?

• The first and obvious way will be to build/pack new versions everytime and send them to the client.

• A second way, which is observed in most apps, e.g Pycharm, is to 'update the app from within the app'. The user clicks on an update button for instance and the magic happens...

I find the second method quite interesting and even better, but have no idea on how to achieve that, hence this thread.
Please feel free to drop any ideas here. :-)