Seen a few threads talking about apps for gps on the iPhone. On the market to give one a go, just not sure which one. From the threads I've read, can't figure which one is best, or better yet will suit my needs. Figured I would make a thread and concentrate the search effort. I don't mind paying for the app, just want something with good topo maps and is pretty accurate. Also has to work where there is no cell service. Mahalo.