Hi! After one year using this app from android, I think I can tell you some of the advantages of using this app in your device.
I know that in some cases, wearing the mobile phone whilst the exercise practice is uncomfortable, but I think that we can use this information in order to encourage our next practice. Having all the files allows you to compare your times, calories, and some other meassures.
Some related articles:
http://www.androidguys.com/2012/09/07/five-for-friday-android-apps-for-tracking-a-run/
You can also make a challenge or a team with your friends or with anyone who wants to share information or compete in a friendly way!!