B4J Question how to End execution of a running app

Either with StopMessageLoop or ExitApplication
https://www.b4x.com/android/forum/threads/how-to-correclty-stop-application.38653/#post-229046

For a ui app if you do not have any background thread mainform.close is enough.

And if I remember correctly this will trigger the mainform_closerequest event, allowing you to do stuff before closing the app

Exitapplication for everything else