While Tapatalk is a good alternative, I favor the mobile site primarily because it is more comprehensive (it is adapted to non-touchscreen mobile phones too), and it is better adapted to the different ways in which the 85,000 people in the forum navigate. Tapatalk can't port things like the User CP's subscription tray.
By the way, Tapatalk has been discussed here already:
https://www.mobileread.com/forums/sho...light=tapatalk