+1 an iOS app maker may be likely. But appOmator already does this -
http://www.appomator.com/
and it's free to download, easy to use and looks to be having some early success.
iPaint gets my vote.
Thanks for the link- I had no idea something like that already existed! Think an Apple app creator that came free with every Mac and didn't charge a subscription would still be a winner though... That's my iLife wish anyway!