Sounds, vibrations, and notifications on your Galaxy phone or tablet Therabody WaveRoller Vibrating Foam Roller For Large Muscle Groups Black WAVEROLLER PKG US Best Buy DITTO Wearable Notification Device DreamZon LightOn Cell Phone Signaler This video shows how vibration works inside a cellphone through a small but powerful internal motor. When the phone is set to vibration mode, electrical current activates a tiny motor with an