Android Floating Action Button in foreground over other Apps?

Question

I'd need an simple example of an translucent activity or something like that to make a button of my own app appear in front of all other things on the device for current android versions? Is this still possible? I tried different solutions from stack overflow, but none seem to fit to the nowadays versions.

I'd like to display a small text or a badge also in this way.

Answer 1

I think can use Bubbles just like this: