Developing a whole app would be a lot of work for people who mostly do this for nothing.
What they should do, however, is install the TapATalk plugin. Then everyone who has a TapATalk app on their mobile device will be able to view a version that is better formatted for their device. It also means that the folks at RF don't have to make an Android app, an Apple app, a Blackberry app, etc.
Tapatalk - Forum App on the iPhone, Android, Nokia, and BlackBerry for vBulletin, phpBB, IPBoard, and SMF