Android app that runs on top of ALL other apps?

Question

Before today I would have said this is just not possible, to have an app that runs overlayed on top of everything else: home screens, apps, dialer, etc.

If you try the f

Answer 1

See this:

Creating a system overlay window (always on top)

Check the comment section of the accepted answer. You will find link to a working example project.

==EDIT==

Link to the project