Tap, Tap brings the double back tap gesture to any ARMv8 device running Android 7.0 Nougat and higher. In the demo video that I embedded above, I double tapped the back of my Pixel 4 to launch the camera app. In this video, developer Kieron Quinn launches the OnePlus Camera app by double tapping the back of his OnePlus 7T Pro. Launching the camera app is not all that Tap, Tap can do, though. Using an Accessibility Service, Tap, Tap can recognize when you tap the back of your Android phone and then perform certain actions, such as simulating a home, recent apps, or back button press.
See Tap, Tap ports iOS 14/Android 11’s Back Tap gesture to any Android device
Tap, Tap is a new Android app that brings Apple iOS 14/Android 11 back tap gestures to any Android device! You can double tap your phone to do many things!