I was thinking, and why not have a spiral knights app? It can allow you to check your knight see if you received any mails and change your equip from your phone. Of course I'm sure that there's more to the application that OOO can add but those were just the things I came up with.
In my opinion, this would be neither lucrative nor practical. Would this be free? If so, what types of 'upgrades' would be offered so that money would be made? If this was not free, what would be the point of it? Who would pay just to see his/her mail or change equipment? Charging for this service would be especially odd for a free game. It would take time and money to make, so it would have to be worth it.