The recent RoadID eCrumbs app for iOS is also good. It has a few features targeted at athletes, such as a "stationary alert" option to notify your select contacts (up to 5) if you stop moving while training. The main function is that it notifies your select contacts when you begin training, and provides a link for them to view your track online. It also has an option to build lock screen wallpaper with your key emergency contact and other info.