The fitness app RunKeeper already lets you check stats on your smartwatch, but what is activity tracking without a public shaming social component? Starting today, the iOS version of the app includes a new feed for viewing your friends' logged workouts along with your own, complete with the ability to comment on and "like" activities à la Facebook. Version 3.5 also adds a leaderboard, which ranks how you stack up against your pals. Hardly earth-shattering features, but the competitive bent might motivate
