Their front page tells nearly nothing about the app. Instead, one half of it solicits registration. This tells me all I need to know about their respect to the users.
With Strava, you record your workouts (run, bike etc) and it will show you where you went, how far and how fast. Then it finds commonly-run “segments” within your ride, and ranks you on those segments against your friends and the world, so you can see yourself improving over time and compare your speed to others.
I should ask a refund, this feature doesn't work for me! ;-)