With this Theremin-inspired instrument you can control sound by moving your finger in front of the camera.
Assign sound parameters to the three spatial axes (x y and z). Then hold something colorful or wear it on your fingertip (e.g. a thimble a pencil or a bottle cap). The Theremin will follow it so that you can change pitch gain vibrato and flanger parameters with a simple gesture. You can also record any sound that you wish to control with your finger.
Moreover change background color select range and octave subdivision switch hand for right- and left-handed people...
Check this video (https://www.youtube.com/watch?v=ewQk6d-aZmQ) to see how it works.