Nike+ is about to turn five years old, and they are celebrating by giving their Nike+ GPS app away for free for a limited time. The app is similar to other run-tracking apps, but it's got a much cleaner interface than most and a color-coded map line so that you can see the parts of your run where you were faster or slower.
Nike+ GPS also offers some fun features other running apps don't, such as motivational messages from Nike's top athletes, personalized PowerSongs to jazz up your run, and even the ability to hear mid-run cheers every time your friends like or comment on your run status.
Even if you are using another running app, Nike+ GPS is worth the download while it's free (it's usually US$1.99). And remember, Nike+ GPS uses the iPhone's built-in GPS, so it doesn't require the separate Nike+ shoe insert.