https://thenextweb.com/offers/2021/02/01/knocki-is-the-smart-home-device-controlled-by-gestures-you-never-realized-you-needed/

TLDR: The Knocki is a brilliant knock-activated smart trigger that can do everything in your home from turning on lights, playing music, setting your thermostat and more.

Remember The Clapper? The sound-activated device was a revelation when it hit back in the 1980s, allowing users to magically turn lights and other electrical devices off and on with nothing more than the clap of their hands.