Magnetometer

Info:

Not all android devices have a built-in magnetometer, so please be advised that it may not work with your device.
Icon and text will indicate if device is compatible once application starts.
Accuracy is dependent on manufacturer.
A magnetic field sensor (also known as magnetometer) reports the ambient magnetic field, as measured along the three sensor axes.
The measurement is reported in the x, y, and z fields and all values are in micro-Tesla (uT).

Settings:

For audible alarm and vibration on high field detection click on respective buttons to toggle.
Change alarm sensitivity by clicking on reading and swipe seek bar to set.

Calibration:

If output readings fail it attempt to calibrate by gently shaking the device or waving the device in a figure 8 pattern.

Permissions:

Vibration: select whether device should vibrate when high signal is detected.
Wake lock: Device will not sleep during operation.