Skimble
Skimble is a mobile app that offers Workout Trainer and Skimble Sports Tracker features.
Workout Trainer mimics virtual personal trainers, giving step-by-step audio instructions through workouts.
Skimble Sports Tracker lets users track sports progress for 45 activities, automatically create maps, and share progress on Facebook and Twitter.
Skimble requires a free online account, on which users can add friends through social networks and follow their activities.