Afaik, taptalk is the most used app for using a forum from mobile..
I think integrating it into a forum is not much work, but I have never used it so far myself..
About the Website, it has a RSS feed that you can enter in pretty much any rss reader or news congregation app.
I can´t imagine anyone installing a FH2 app, if all it does is show you that there is news once every few weeks.. But then, I also don´t use facebook, so maybe my judgement of what is useful is not always the best