Knock is a shortcut app that lets you control your Mac by simply knocking on it. Tap the sides of your laptop and it runs any shortcut you want — screenshot, open apps, mute sound, and more. It uses your Mac's built-in accelerometer to actually feel the vibration of your knock and react in real time, no extra hardware needed - just knock and go.

Knock turns taps on your MacBook into instant actions. Switch tabs, change desktops, play/pause music, open apps, run custom scripts, or take screenshots - all with a simple knock. Tap the desk beside your laptop or knock on the MacBook’s chassis (not the trackpad). Knock uses the built-in accelerometer in Apple Silicon MacBooks to trigger customizable shortcuts.