We mostly wake up our Android devices by pressing the power button but on some other Android devices you can use voice command to do so. For others, you can double tap the screen to do so. This feature is not available on all Android devices except devices like HTC One M9 Plus, Xperia Z5, Xperia Z4, and LG G4.
But worry no more because we’re here to inform you that you can add this awesome feature to your Android device too. All you need to do following our simple guide down below!
STEPS
1. Download and Install “KnockOn” app from Playstore (Link).
2. Open the app.
3. Tap on “Start the app” button.