>The Geocoding API may only be used in conjunction with a Google map; geocoding results without displaying them on a map is prohibited. For complete details on allowed usage, consult the Maps API Terms of Service License Restrictions.

https://developers.google.com/maps/documentation/geocoding/

I wanted to use this API for a simple app of mine too but in the end didn't because of this. Used Mapquest instead, which seems good too.