Pretty simple. Rather than rely on the app or a visit to the Tower, add a screen or display by the mark counts in the menu that lists current faction rep. Every other game in existence that uses a rep system has a convenient list of faction reps. Destiny needs one. That way, we can see a full list of our rep with all the factions in-game, and given that it seems like there will be a quickly growing number of factions, all the more reason. I shouldn't have to run to each vendor (if they're even accessible at the time) to see where my rep is at with each one.