One of my favorite iOS image editing Apps, Photoshop Express has just been updated to version 2.0
Photoshop Express 2.0 remains a free App that now has more support for iPhone 4's retina display as well as multitasking.
New Adobe Camera Pack
If you want to go further Photoshop Express 2.0 now offers an in-app purchase of the Adobe Camera Pack. This in-app purchase gives you additional features like an instant Review feature that is similar to what you find on traditional point and shoot and DSLR cameras. For example, when I take a photo on any of my other cameras, I see the photo for a few seconds on the LCD to make sure I got the shot. However, after you take a photo with the built-in iDevice cameras the photo goes directly to the camera roll without showing you what it looks like first. Granted you can tap to see the photo that you've just taken, but then you're missing out on taking more photos while the action is still going on. With Photoshop Express you can now set a 2 second or 5 second review that will show you the photo AND allow you to delete it, right after you take the shot to make sure it's what you want. You can just keep right on shooting without any additional navigation. You also get a timer for taking shots that you want to get into or have the iDevice be totally steady on a tripod. You can also take advantage of Adobe legendary Noise Reduction features:
You can download Photoshop Express 2.0 for iPad, iPhone and iPod touch for free here from the 
$3.99 in app purchase, get serious! That is just a blatant cash grab. If the Photoshop team priced the app to begin with at .99 cents or 1.99, then provided update with new features like everyone else does that would make sense. How come Apple can release incredibly robust apps like iMovie and Garageband for the iPhone and iPad at $4.99 and Adobe who should make the best camera app and editor available on the mobile platform can only muster the very weak and limited Photoshop Express, then have the nerve to charge $3.99 for 3 features it should have had to begin with. The Photoshop team better hope Apple doesn’t release a mobile version of Aperture.
To me Camera+ have more features. The only thing that I found useful in PS is that allow me to to review the picture like a real camera. Camera+ has more editing features.