Try it
Blackboard: white chalk on a dark grey board.
Kinetitude follows your hands with your camera. When you press Start, your browser will ask to use the camera. The picture stays on your computer.
Use a laptop, desktop or phone, with the sound on. Stand back a little. Point a finger to draw a fine white line. Sweep a flat palm to smear it into clouds. Each try lasts two minutes.
This is a short test version. The kiosk in a gallery or hospital has more palettes, gestures, music and printing.