Amplitube IOS is still my fav amp sim ever. I have been a pro guitarist for +20 years and owned many tube amps. There's a couple of amps in AT IOS that to me are unmatched by any other amp sim out there, software AND hardware. The Kempers and Axe stuff to me sounds mediocre in comparison. With my Ipad, my Irig HD2 and the little Blueboard, I have a killer sounding, low cost setup that sounds better than the fancy expensive hardware.
I also have Tonex on my Ipad Pro and AT 5 on my desktop, but to me not even these are a match. The specific amps sound and feel very different. At some point I even considered getting an old computer just so that I can run Amplitube 4, to me it's the best amp sim ever created.
BTW, AT IOS doesn't work at all in Logic Pro on the Ipad.