Gesture Synth (gesturesynth.app)

Gesture Synth at gesturesynth.app is a webcam chord synth that splits the job across your hands: the left hand plays the main chords and the right hand adds more. You pick a sound and record a 15-second clip.

It is free in the browser with no install. The site states that tracking stays on your device, which is one of only two versions in this category to publish a privacy claim at all.

There is less here than on the larger versions, and that is the point. If you have never used a gesture instrument and want to know within thirty seconds whether you enjoy it, this is the least cluttered starting point.