I have - I've seen it in use on one of the other boards I frequent, but with mixed results. Unfortunately Tapatalk doesn't support UBBThreads.

From the Tapatalk site: (http://www.tapatalk.com/plugin.php)

Q: Which forum system does it currently support?
A: Currently phpBB3 3.0.x, vBulletin 3.7.x/3.8.x/4.0.x, Invision Power Board (IPB) 3.0.x and Simple Machine Forum (SMF) 1.1.x/2.0.x are supported.