HTC One M9 - Manual (Page 89)

Your Phone Interface 76
4. Select the Motion Launch gestures you want.
Wake Up to the Lock Screen
Go from sleep mode to the lock screen without reaching for the Power/Lock button.
1. Lift the phone in portrait orientation.
2. Immediately double-tap the screen.
Make sure you're not touching the screen when the phone vibrates.
Wake Up and Unlock
Go from sleep mode and unlock HTC One M9 to the last screen you were using without reaching for
the Power/Lock button.