there ar many apps that use GPS, here are the top three rated:1. WazeWaze is probably one of the best apps on the iphone. It is a social networking meets GPS application, and it allows you to share your location details with Wazer friends.The awesome part is that you can report traffic jams to others or locate nearby Wazers.Finally, Waze is a social app that lets you connect with other Wazers via chatting and map pinning. The BEST part, though, is that its main purpose is to help you navigate traffic.2. iWantThis is a cool little app that lets you know what is around you. If go on a lot of hiking trips and you don’t know were you are that well, this helps you find gas and places to eat.Even though iWant wants you to buy the full app, don’t…the free version is awesome. You can find anything around you within seconds!3.GPS TrackerGPS Tracker is very good. While it is a little tricky because you have to apply for a free code, it is a nicely done app.Basically, it tracks your phone, so if you are lost in the woods, someone can find you. I hope to never need it, but it will be awesome if I do!While InstaMapper’s iphone interface isn’t all that exciting, the web tracking is very cool if you are a hiker or geocacher. The iPhone updates every few seconds so folks back home can see where you are on the map!