firstly its not a free app so I didn't want to download it just to see what its like. I use an Iphone 4 and I can quite comfortably view forum web pages without the need for the app (which is generic and not a mixoff.org app).
My problem is that when ever I change pages, forum threads or access any content, I get a pop up message telling me about the app. I can cancel the pop up message and so if it popped up when I first visited the site it wouldn't be a problem. The thing is that it appears all the time....which gets very annoying!
Not sure if your able to change any settings at all so that the pop up is not as frequent?