FeralHeart takes less energy for a computer to run than ITunes - so, I don't think that's really even a real problem with this idea. Or maybe I' underestimating the amount of people playing FH with slower computers. xD
Even if it was done, considering the amount of money and time it would take, The IPod Touch has a screen that's much too small if you're thinking of actually putting the entire game into an app.. think about it, without keys to move your character, there would even need to be a new interface specifically for it that allows you to move while touching the screen. It wouldn't be even worth it with the amount of annoyance having to play it on such a tiny screen would cause.
However, if it was created for the IPad, which has a much bigger screen, it'd be possible to play it. If you want to fool around with Apple, of course. Which you normally don't. :|