Solution:
From the home screen of the watch, swipe left you can access the watch face, long press the button, adjust brightness, about and turn off in the settings of the watch.
Set the watch face: Tap and swipe up, you can access watch faces. Tap on your selection and confirm by tapping ok, the watch face will update.
Long press the button: Tap the check mark next to the activity to make it quick start by long press. You can set to quick start outdoor running, treadmill, cycling and walking.
Adjust Brightness: You can adjust the brightness by adding or subtracting keys.
About: You can check firmware version and Bluetooth address.
Turn off: You can turn off your watch.