Tiny Apps consists of some of the most useful tools one could have atop other windows: notes, recorder, paint, music player, and calculator. It's actually s a package of 5 useful floating apps that stay on top of all other apps.  You can run several windows of the same Tiny App.

This is the lite-version of Tiny Apps. It has a limited amount of features (available in Tiny Apps Pro: dock windows to the left side of your screen, change the window's transparency)

Check out Tiny apps at the link below:

Google Play Store Link