I like Apple's HDR feature, but the lack of anti-shake in Camera.app really bugs me. OTOH, I haven't found a third party app with Apple's HDR.
Does such a magical app exist?
Yes. The only I trust/use myself.
http://itunes.apple.com/us/app/truehdr/id340741871?mt=8
Good luck, and hope you like it! Use this one- it's the only legit one out there.
Does it use Apple's HDR? It looks like you need to hold the camera still while it takes 3 pictures, which is not what I want..