I have heard that you can manually switch carriers when using Project Fi. How do I go about this? What is the easiest way?
Edit: Is there an app that does this too?
You can easily manually switch carriers in Project Fi:
Head into the Phone Dialer app that came with your Nexus phone, then type in these dialer codes to manually switch carrier:
You can also download the Fi Info app, which automates the process a bit with a widget (I use it all the time).
Singal Spy is the app that I use to do this.
It also shows you at a glance what network you are currently connected to: