Never used it before, but I may use it for english forums. Until now I used computer for checking forums in english and italian (I use auto translate for italian -> english via google translate in chrome), but I do check forums in my language (slovenian) on phone very often - every few minutes when I have time.
I heard about Tapatalk before but was too lazy to check it out.
I think that I will check forums in english more often now with Tapatalk, problem is that I'll still check italian ones with computer with chrome for translating and slovenian forums via safari on mobile since most of them don't support or work with Tapatalk.
Then again, it is still ok to read TPR forum on mobile, at least on iPhone with retina and other high resolution phones. And there is this "feel" if you are actualy on the page itself, you know that this is TPR forum and it is not the same as it is on Tapatalk. We'll see how it goes.