Found this great and currently free app called meshLab for IOS that lets you import your models and view them on the ipad in a interactive method that includes, rotation, zoom in , zoom out and 1 interactive directional light with self shadow. The apps lets you import and view a wide range of 3d formats like OBJ, STL, OFF, PLY.
This is a great find as I can import reference anatomy models and also show off my own sculpts! For a test I imported my Ninja crap sculpt in STL format which was roughly 500K tris and the app handled it fine. Really happy I found this app, definitely worth checking out if you want a fast and easy way to shop off your models.
http://itunes.apple.com/au/app/meshlab-for-ios/id451944013?mt=8
