An app has been suggested quite a lot of times already, actually. In every case, it was rejected because the time (and possibly, money) it takes is disproportiate in relation to the small benefits like for example mobile posting on the forums. Besides, the storygames are usually quite playable on mobile devices.
So yeah, unless one of the site member (*nudge* *nudge* *wink* *wink*) is willing to build an app themselves, I don't think this is going to be accepted