HTC One M8 User Manual page 65

Making a call with Quick call
When the screen is off and HTC One is in sleep mode, easily make a call by
just swiping and using voice commands.
§ This feature may not be available in all languages.
§ Make sure Motion Launch gestures and Quick call are turned on in
Settings > Display & gestures > Motion Launch gestures.
§ If you've set a screen lock with credentials, you'll be asked to
provide your credentials first before you can make the call.
1. Lift the phone in portrait orientation.
2. Swipe down the screen right away. You need to start swiping from
the upper half of the screen.
Your first week with your new phone 65