Signal Spy was developed for users of the Google MVNO called Project Fi, now Google Fi. Therefore, they are currently the target users of our app. However, the app can be used by anyone on any network! Band detection is available on all carriers with Android N. All non-Fi carriers will not be able to use the Fi specific dialer codes (T-Mobile, Sprint, Next, Repair), but they will be able to use the history page. So apart from the Fi specific features, this app is useful for carriers around the world!