Turn Tap on by briefly pressing the on/off switch. The switch is located on the top of the thumb ring in the center of the oval.
When you turn Tap on, you will feel one, two or three vibrations indicating the battery charge level. When your Tap is on the blue light around the on/off switch will blink slowly.
Turn Tap off by briefly pressing the on/off switch. You will feel one vibration when Tap turns off.
Here is a video which demonstrates how to wear your Tap and how to turn it on and off: