This app enables you to know the radioactivity level of Tokyo city. This information is based on the records provided by Tokyo Metropolitian Institute of Health and measured at Shinjuku. The data is updated every one hour by the several detectors.!!BEWARE!! This app won't turn your mobile into a Geiger counter! It displays data which are sent by the detectors of the Tokyo Metropolitian Institute of Health.!! This is working for TOKYO ONLY. !!