I bought this App a few weeks ago and I love it!
TUAW has a great review and more info about the app, Photogene:
Photogene is kind of like a miniature Photoshop for the digital pictures you take on your iPhone.
It has a boatload of functions, which will let you fix and enhance your digital images without having to offload them to another image editor on a Mac or PC.
Here’s some of the functionality:
- Enhance photos with color adjustment and sharpen tools
- Crop and straighten photos
- Add text balloons
- Create a variety of frames
- Adjust Histogram
- Correct Gamma
- Increase/decrease saturation
- Adjust color temperature
- Multiple undo and redo
(Read full article Photogene is a photo genius for your iPhone )