http://mobile.photoshop.com/android/

Perfect your pictures with Photoshop Express on your Android phone. Simply drag your finger to crop, adjust color, apply effects — you name it.

* Crop, rotate, and color-correct with the touch of a finger.

* Add soft focus or change to black & white with a click.

* Go classic by adding a sepia tint.

* View local and online images with an intuitive Photo Browser.

* Apply one-touch effects like Warm Vintage and Vignette.

When your image is perfect, make it your phone background.

Picsay is also worth checking out for free photo editing. And for a camera app with loads of cool effects try Vignette.