NEW: small limitation due to Google policy changes: Ending a call: The FMC app can no longer directly end native (cellular) calls. As a work-around the FMC client now sends DTMF **49 to let the server hang up the call. This only if it has a data connection and is registered. If not then the user has to end the call manually by pressing the red button in the native call screen.
App allowing your smartphone to become an internal client of your Forum 500(0) Telephone exchange.