Google Maps is installed by default. This only works with a connected smartphone from which it obtains the current data via the Internet. However, you can also use an onboard navigation system.
Here you may find some navis apss that can help if you have already bought the SPH-DA120.
http://www.appradioknows.com/navigation
I recommend NAVFREE GPS LIVE or CoPilotGPS, which I often use. Both only need an internet connection at the beginning to load their maps for offline mode (only at the first start).
I hope this helped you a little.
Greetings redwood_ch