If you know your way around a smartphone, then you're surely aware of their versatility. There's a substantial number of every-day tools and devices a smartphone can replace, such as a camera, a radio, an alarm clock, a flashlight, a sound recorder... we can go on. The humble compass is also on that list, as you may or may not know. Inside your handset, there is a tiny magnet spinning around an axis and pointing at the planet's north pole.

Okay, we lied. Compass functionality in phones and tablets is enabled by something a bit more sophisticated – a sensor called a magnetometer, which is ...