Any good photo shop apps for iPhone 4S?

I want an app that will make my skin look better without it blurring it. I don't want an app that's just filters and whatnot.

Pixlr o matic is really good but if it's just for filters and such then retrocamera

I would definitely recommend iPhoto by Apple. You can use the repair tool to fix anything wrong with the photo. The app costs $4.99. I can't think of any apps that are free.
I would also recommend a photo app called Snapseed. I think it once got iPhone App of the Week.