I'm away for most of this week, but I'll take a look at it over the next couple of weeks :) I'm concerned about the security aspect of things, as I wouldn't want to find it opens lots of holes in the server.
I promise I will look in to it soon (hopefully in the next couple of days, certainly in the next couple of weeks).
It looks like users have to pay to use the tapatalk application (unless it is read only), so an alternative would be to use a mobile style on the forums - which would be free to all. It is easy to make it so that a button appears on the home screen of the iPhone that would link directly to this version. :)