Batphone is a research tool which tests a method invented in 2010 for locating yourself while indoors. It's mean to be an alternative to GPS or iBeacon, and it works by using the microphone to record room ambience. These acoustic room fingerprints are used to recognize previously-tagged rooms when they are revisited. For comparison, it also shows the position retrieved from Location Services, which determines your coordinates using radio signals from GPS satellites, wifi and cellular base stations. Our experiments have shown that Batphone's new acoustic method is more accurate than the radio method. Try it for yourself and let us know what you think!