The levels of protection Secure Phone offers are not solely limited to the IMSI catcher app. First off, Secure Phone is encrypted and only sends and receives encrypted data. And to do that, Secure Phone relies on open-source encryption protocols that also provide ways of detecting MiTM attacks, including possible IMSI-catcher activities. Third and far not least, Secure Phone SSL connections follow the best practices of utilizing maximum security of keys and data. However, a vast majority of the Internet, including bank systems, still use poorly secure implementations of SSL encryption.
Our IMSI-Catcher Detector stays connected to our backend services and maintains an updated database with cell towers across the globe. The app monitors connections to cell towers and matches their availability in the database. Not only that, the app monitors communication with cell towers and detects various exploit patterns that IMSI catchers follow. Note that the IMSI-catcher device itself does not perform any protection actions: it just warns you about IMSI-catching devices nearby.