Auria looks great! I used Cubasis on my iPad mini, and then moved to the iPhone-compatible MultiTrack DAW when I figured out my iPhone could do this just as well.
Actually, Auria is a DAW that supports my Focusrite Scarlett 18i20 and many more and that's on any current IPad. And there is a variation of Cubase from Steinberg.
http://auriaapp.com/Products/auria
http://www.steinberg.net/en/products/mobile_apps/cubasis/start.html
!