Play with Phone Multi-Camera

Modern phones have several cameras on the back, but normal apps usually use only one.
This is confusing and interesting to me.

Simple goals:

• Use Android Studio to see what the camera APIs can really do.
• Try to open more than one camera at the same time, if the device allows it.
• Learn basic camera calibration and test it with real images.
• Build a small demo that does something fun with two views, for example depth, 3D feeling, or simple alignment.

I do not expect to solve all hardware limits. I just want to understand what is possible on a normal phone and learn some computer vision skills on the way.