2. Hunt for treasure
One of the most unexpected things your smartphone can do is search for metal. If you own an iPhone, download a free app called Metal Detector. This app taps into your phone’s built-in magnetometer, which helps your phone detect the X, Y, Z axes for things like the compass.
Metal Detector won't detect everything that's metal, but don’t discredit its ability. Point your phone’s camera toward the metal objects and turn up the dial to increase the intensity. You’ll be surprised by the things it picks up. The app detects any metal that is magnetic.
If you don’t have an iPhone, a similar app (also called Metal Detector) is available for Android devices. These apps share the same name; however, they were created by different developers and have slight differences in the way they operate.