The edge screen on Galaxy S7 Edge brings some cool features to the device, including the option to reject a call with a preset message by covering the heart rate sensor for 2 seconds. To quickly reject a call with message on Galaxy S7 Edge, do as follows:
1. Open the Settings app on your S7 Edge
2. Tap the Edge Screen option under the device settings
3. From available options, tap to open the Edge Lighting settings
4. Make sure the Edge Lighting button is toggled On and then tap the Quick Reply option
5. Toggle the Quick Reply ON
6. Type your reject message in the Quick Reply Message box and you are all done.
7. From now on, if your device is facing up down (turned over) and you are receiving a call, all you have to do to reject the incoming call and automatically send the preset message is placing your finger on the Heart Rate Sensor (next to the camera lens) for 2 seconds.