This is a Pebble Smartwatch companion app, need to be used with Pebble Smartwatch.
HOW TO USE
Start the app and connect to pebble smartwatch, start the app in pebble smartwatch. Tap the start button in device—cover the camera lens with your fingertip completely and gently—wait for calibration result - the heart rate.
Refer to help section in app for detail.
NOTES: This app is for entertainment purpose only. The measure result can only be used for your reference. Consult a doctor if you have any health concerns.