A free app for Android, by Kobayo Apps.

Ghost Spirit Radar Detector is a ghost detector and paranormal radar app that uses the phone’s sensors to detect paranormal activity, such as ghosts, spirits, and any other type of force or energy that is capable of modifying and varying the magnetic fields of our environment.

When the radar is turned on, the phone’s sensors will begin to receive signals, which will be shown on the screen — green illuminated dots for the strongest, yellow for the medium, and red for the weakest. The words displayed on the LCD can also be interpreted.