A free program for Android, by RocketJump.

Are you a VFX artist looking to do something different? Maybe you’re a student learning to make movies, or an amateur who wants to make a film for fun and share it with your friends. Or are you an effects enthusiast who wants to try out something new? In any case, you should definitely check out the free version of Chromascreen. 

In this app, you can create a background for your phone or tablet screen. This is great for when you are filming on a device, and want to make sure that you aren't shooting on the screen of your device. You can use it for mobile or tablet screens.

This is a very simple tool to use. The process is very easy and intuitive. First, select the "Use as Background" option. This will put a red marker on your screen. Then, move the green laser pointer over the red marker, and you're ready to start.

The green laser pointer indicates where the green screen will be. Now, just move the camera to the desired location and start shooting. The app will track your movements and adjust the background accordingly.

If you need to adjust the background further, just move the green laser pointer to the desired location.

You can also adjust the size of the background.