Signal Spy started as a companion app for Project Fi called Fi Spy. It provides information about your connectivity via cellular and wi-fi connections. It also gives you the ability to control that connection via dialer codes and monitor your connections with a history log. We also provide quick links to Fi communities. That is where we started, and we've made our features compatible with more carriers in the US and worldwide!

https://play.google.com/store/apps/details?id=com.novvia.fispy&hl=pt_PT