Gogo Navigator USA & CAN is a real-time, turn-by-turn 3D navigation app for the iPhone. It features real-3D, Text-To-Speech voice guidance, Advanced Lane Guidance, real Signpost display, millions of onboard POIs and much more.
Where all the GPS needs an internet connection to proceed, Gogo Navigator just loads the map to your device on the initial download and thereafter no need for any connections! Just Go with Gogo..
Have a look on the below link for more details.http://itunes.apple.com/my/app/gogo-navigator-usa-can/id408828343?mt=8