I have just started working as software developer. My first programming project is creating an app for Android version 6.0.1 to Garmin fleet 790 GPS-navigator.
I should create an overlay window app which drawing on top of every other apps. I need also use Android drawing routines for creating a custom buttons.
How could I create overlay app which allows to use other app same time when my app is on.
Lot of thanks for everyone who can help me!