I want to bring up an idea for Nabble. Hugo (or anyone else for that matter)... have you looked at incorporating Tapatalk into the Nabble forums?
http://www.tapatalk.com/api/api.phpTapatalk already supports phpBB3 3.0.x, vBulletin 3.7.x/3.8.x/4.x, Invision Power Board (IPB) 3.x and Simple Machine Forum (SMF) 1.1.11+/2.x. I don't know what the API looks like or how much work this would actually entail, but having a browser-independent real-time smart phone app with deep forum interactivity would be ideal.
If this were to be something that Nabble wanted to tackle, what kind of time investment would be required? 10 hours, 1000 hours? I really have no clue.
shane