You are not allowed to use the free Google Maps API on the iPhone if the App is for Sale unless you use Android with Google's store. See 9.1.2 Exceptions: https://developers.google.com/maps/terms
(Free Access) does not apply if your Maps API Implementation is used in a mobile application that is sold for a fee through an online store and is downloadable to a mobile device that can access the online store.
A commercial Maps Api License is too expensive for most cases.
However using Apple's Map Kit will switch you to AppleMaps and that should be free.
