I'm wondering whether Xenforo sees a mobile app as something that should be left to third-party developers or whether an app will be offered or included in a future update--like 2.0.
Our current focus is XenForo 2.0, following on from that it will be RM 2.0, MG 2.0 and ES 2.0. Beyond that, there are no immediate plans for an app, but it could be something we consider in the future as we would with any other open suggestion.