Magnetometer is a less known sensor. It equips web browsers with the ability to
read the magnetic field [https://simple.wikipedia.org/wiki/Magnetic_field]
strength using the built-in magnetometer device sensors and the W3C
Magnetometer
API [https://www.w3.org/TR/magnetometer/]. It might be useful in some specific
use cases such as peripheral devices (like a gamepad, to control the user’s
gestures) or to… make a web app demonstrating how a compass works, and so on. It
can also aid in indoor navi