Bongo Cat
bongo.cat
Press keys on your keyboard and a cat plays bongos in time — every key produces a different drum sound and the cat's paws animate to match. An interactive musical cat with no other purpose.
Why it is useful
Technically simple, deeply satisfying. The animation and audio sync is tight enough that you can actually play rhythms, and the visual feedback of the cat's paws moving makes it more engaging than a basic drum machine. Good for 90 seconds of stress relief or introducing small children to the idea that keyboards can do things other than type words.