I believe you have noticed a sudden influx of floating apps in the recent times. Floating apps are similar to desktop apps that run within a window so that you can drag and move it to any part of the screen and have access to the rest of the screen. We can also develop similar apps with the java library given below, but only with a wrapper. I hope someone will come up with it.
[APP][2.1+] StandOut - Create Floating Android Apps with this Open Source Library - xda-developers
[APP][2.1+] StandOut - Create Floating Android Apps with this Open Source Library - xda-developers