Flutter: automatically resume app from background service

Question

Is there a way to automatically resume a flutter app from a paused or inactive lifecycle state with a background service?

Similar to when the WhatsApp app received a call while it was paused or inactive.

Answer 1

You need to use a couple of things together:

• Use push notifications to wake up your app:
  https://pub.dev/packages/firebase_messaging
  To start your app using push notifications refers to this post:
  https://stackoverflow.com/a/48405551/4335775
  
  
• Use CallKit (IOS) or ConnectionServices (Android) to show the upcoming call screen. By the day of this answer there are only a few packages to handle these things, here is one that can handle both platforms:
  https://pub.dev/packages/flutter_callkeep

If you want a completely different thing and need to run some background process, there are bunch whole of things you should know first.
I suggest beginning here: https://flutter.dev/docs/development/packages-and-plugins/background-processes

Here is a usefull package to work with background processes that should be constantly running:
https://pub.dev/packages/background_fetch

The app can only be waked up with explicit commands. The user must hit the button. And there are ways to handle the input, messages may pass parameters, you can save the previous state in the database or shared preferences, etc.