If there is no official android app for this forum it should be! 
There is no such official app for any forum Lol. Just use tapatalk. That should be fine.
Use tapatalk and there are apps designs for some of the forums to make the surfing experience easier. Like you can access this forum right from the phone or tablet but It's difficult to surf and specific apps for the forums makes It easier. Here Is the review I found about tapatalk http://www.imore.com/best-forum-app-iphone-and-ipad