The Paranormal Spirit Bell is a new type of trigger device for Spirits to use. If any of the sensors pick up a change then the Bell will ring. Simply place the device in any area, click the "Calibrate" button then move away from the device. If you move the device after it has been calibrated you will need to recalibrate, simply click the "Back" button, move the device to a new area, then click "Calibrate" again. The sensors used are: Magnetometer - This senses Magnetic and Electromagnet fields around the device Accelerometer - This senses any device movement and the slightest vibrations around the device Barometer - Detects any change in the Ambient Air Pressure around the device Compass - Detects the slightest change in magnetic interference to Magnetic North GyroScope - Detects the slightest movement of the device Orientation - Detects the slightest movement to the position of the device If your device is missing any sensors, the app will still work perfectly well without them. ** Disclaimer ** Use at your own risk, I cannot be held personally responsible for you or any outcome (paranormal or otherwise) from using this app!