If you haven't signed in with your Facebook account for few months the sign in token will expire (in about 60 days) and you will have to go through the Facebook login again to get a new token.
You can do it in here http://www.sports-tracker.com/profile/edit

If you have problems with sharing to Facebook, check in your Facebook account that you have given us the correct rights. 
1) Open your Facebook account with a pc
2) Open privacy shortcuts (the key lock in the upper right hand side of the website)
3) Choose "See more settings"
4) Choose "apps" on the left hand side of menu
5) Click on Sports Tracker
6) Check that you have set
- app visibility to "friends" or "public"
- post on behalf of you 
- if you don't see "post on behalf of you" option, then remove the app from FB (same settings) and logout from your Sports Tracker account and login with FB. This might also be helpful if all the settings are correct but you still can't post.