Originally Posted by DuffMan
Assuming you're somewhere with cell service.
I've seen my iPhone 4 nav fritz out deep in the Smokies where there was no cell service. Garmin 60 CSX never missed a beat.
you don't need cell service to use app... it works off the GPS on the phone just like a handheld does. You just down load the area you will be in and you are ready to go. Maps are free and you have a wide choice of maps you can download. I have never had an issue with the app, in fact when my friends Magellan handheld lost signal, we had to use the app to get use back on track.