HTC One M9 User Manual page 307

2. Hold HTC One M9 and the other phone back to back.
Make sure that the NFC area (shaded part) of HTC One M9 and the other
phone's NFC area are close to one another. Experiment by slightly moving the
phones until a connection is made.
3. Tap the screen.
The shared content appears on the other screen. For some items that you've shared
(such as contact information), additional instructions on how to save the item will
appear on the receiving device.
Wireless sharing 307