Motion Gestures - HTC One M8 User Manual

If you've set up a screen lock, you'll be asked to provide your credentials
before HTC One unlocks.
If you've set an event reminder or an alarm, you can snooze or
dismiss the event or alarm right from the lock screen. Just drag
or up.

Motion gestures

Use motion gestures to mute HTC One, lower the ring volume, and more.
Lift phone to auto answer a call
To automatically answer an incoming call, lift the phone and look at the
screen first to see who's calling before you hold it to your ear.
You can turn this feature on or off. Go to Settings, tap Call, and then select
or clear Auto answer calls.
Your first week with your new phone 47