GuitarJack and some experimentation
I’ve been meaning to do this for a while now although I’d wanted to use my iPad 2, but it seems now that it won’t be usable as an input device for some reason. Anyway, I used the GuitarJack in my iPhone 4 and it works very well. Using it with GuitarTone is good too, which I wasn’t expecting as what I wanted to achieve was a non-guitar like sound. I got close enough.