Adobe has updated Photoshop Express for iOS 4.2 devices, and it now supports the Retina Display for better quality images. The app is faster and more responsive and adds background uploads and multitasking support.
The app provides a limited subset of Photoshop functions, like crop, straighten, rotate, saturation, contrast, sharpen and other basics, and it includes a way to add frames.
If you have a Photoshop.com account, you can access any of your stored pictures. People who updated today are complaining that the app took some features away if location services are not enabled -- something that wasn't true in the older version. Specifically, if location services are turned off, the app reports that "Photo metadata cannot be added or preserved, and browsing through photos in the library will be disabled."
Photoshop Express is free, but it now requires iOS 4.2 or greater. It runs on the iPad, iPod touch and iPhone.