It's basically for categorising you call log by contact type (i.e. business, personal or other) and then allowing you to send your boss an email come month end of all your business calls costed at a fixed rate per min or second (cos our service providers don't have the functionality to connect to their billing systems via webservice) to claim your business calls.
Going to start work on a fitness system soon... the guy I am working with has a pretty big idea... webbased system with integration into mobile app... with stuff like meal planning, calorie counting, exercise tracking...