Time for my 2 cents...
1) I can offer a mobile skin, but tt is sooo much faster in loading, I have member who specifically asked for it.
2) It provides a very easy to use interface - much easier to reply to messages, post, etc. The native look makes you feel right at home.
3) Yes, you can pay a fee and make the app free for your users, or even charge them. I see IB only offers that choice, no option to pass the complete cost to the member.
4) tt may have its issues, when found they usually release a fix within 24 hours. For a one time cost of $3, that is some sick service.
5) Over 10,000 forums are in there. Why? Must be the ease of use.
6) I have found forums in there that I would never have found before and am a member as a result.
So if XF and tapatalk could get along (and they can), then why not offer it - even if it is for one member?
So much tt hate here...
and personally, I prefer one app that gives me access to all my fav forums, where I click 3 buttons from the home screen and I am logged in, seeing the latest 20 posts.
Browser: navigate to forum, switch style (maybe), login, preform search for unread. More steps and typing. During which, I am loading a whole bunch of un-needed data... talking 10x as much sometimes...
