RunKeeper Free is a no-cost but still full-featured version of RunKeeper Pro, a fitness app that helps runners (and even hikers and cyclists and the like) track the speed, pace, distance, and location of their workouts. The app has a streamlined, two-button interface--Stop/Start and Pause--and a large display that shows time elapsed, current speed, pace per mile (or kilometer), distance traveled, and GPS strength. What makes RunKeeper Free so useful--and motivating--is its ability to track the history of your runs, showing a quick list of the date, start time, duration, and distance covered for all your runs, and even mapping out each workout with your iPhone's built-in Maps and location data.
RunKeeper Free provides plenty of functionality all by itself, but for even more features you can sign up for a free account on the RunKeeper Web site to access more detailed data (such as weekly workout graphs), post your runs automatically via Twitter or Facebook, and more. RunKeeper Free isn't perfect--for example, you have to manually shut off wifi for better GPS results each time, and it isn't easy to fiddle with your iPod in the middle of a run--but this app is a must-download for anyone who runs and owns an iPhone.