Only nav app I know to work without cell service

If you start your trip , say in Vegas and go through Mammath lakes and Yosemite where there is no cell service,,, it still works. The map is in the memory of the phone so its not needing data. And its still works with my phone even without cell service. My only gripe would be the cost to get the other regions. I bought it at an introductory price for $19.99 or 29$ I should have got every region.

Runamukroadie about NAVIGON U.S. West, v2.12