Android Phone Transformed to A Metal Detector!?

I think you have already heard that it is possible to control robots using Android phone (G1) and amazing applications keep being shown up. At this time, someone transformed Android phone to a metal detector using special application.This is possible using a compass module settled in a phone. It detects small changes of the magnetic field and then judges weather metals are near the phone or not. Actually we can see an accurate and well-functioned metal detector in airport but it is surprised that we can utilize cell phone as a metal detector.