THE BASICS: This app tracks any of 21 distance-based activities and logs the details. Real-time cues help you monitor workouts and keep on pace. And you can analyze your training online, track a friend working out in real time, and participate in public challenges.
COST: Free; a Pro version ($5) adds functions like interval training and a low-power mode.
SOCIAL SKILLS: Endomondo focuses on social functions as motivation. Pep Talk lets you follow friends live and type in messages that are read aloud to them as they compete or train.
BEST FOR: Connecting with like-minded folks. Once you've got a group together, create challenges—anything from fastest 10K time to the most running, swimming, or cycling mileage.