These are generic codes and the application is basic in that sense - but it does have a good amount of metrics which impressed someone like me who wants to start with OBD tools just now. Also the GUI is much cooler, you can set 5 of your favourite metrics on the main screen with one big one in the centre.. and other stuff like that.
Also what impressed me was you can check and clear engine codes from this - I didn't expect an 'iPhone' app per se to do that you know.