From Adobe Systems:
Bring the fun and creative possibilities of Adobe Photoshop software to your iPhone and iPod Touch with Adobe Photoshop Touch.
Transform your images with core Photoshop features. Combine images, apply professional effects, and share results with friends and family through Facebook and Twitter -- all from the convenience of your iPhone and iPod Touch. Enjoy most of the same features as the iPad version:
Use popular Photoshop features, such as layers, selection tools, adjustments, and filters, to create mind-blowing images.
Improve your photos using classic Photoshop features to bring out the best in your photography. Apply precise tone and color adjustments to your entire composition, a particular layer, or a select area.
Create something other-worldly using painting effects, filter brushes, and so much more. With Photoshop Touch, the creative possibilities are endless.
Make your images pop with graphical text. Apply strokes, add drop shadows and fades, and more.
Take advantage of your device's camera to fill an area on a layer with the unique Camera Fill feature.
Quickly combine images together. Select part of an image to extract just by scribbling with the Scribble Selection tool. With the Refine Edge feature, use your fingertip to easily capture hard-to-select image elements, like hair.
Start a project on your iPhone or iPod Touch and finish it on your iPad* or back in Photoshop** at your desk using a free membership to Adobe Creative Cloud.*** Your projects are automatically synced between your devices.
Free membership to Creative Cloud provides 2GB of cloud storage.
Work on high-resolution images while maintaining the highest image quality. Images up to 12 megapixels are supported.
*Requires separate purchase of Photoshop Touch for tablet.
**Adobe Photoshop CS5.1 or later.
Creative Cloud may not be available in all countries or languages and may be subject to change or discontinuation without notice.