Adobe's Project Rigel, which will arrive in October, offers a new Photoshop alternative for mobile devices. It'll arrive on Apple's iPhone and iPad first, with an Android version to come later. It's geared chiefly at retouching photos -- changing things like brightness and colors while letting people smooth out skin blemishes and widen eyes.
On the left side of the screen, you get options to adjust how retouching tools apply changes. Once you're committed to a change, tapping the check mark in the lower right corner bakes it into the image -- but all changes can be reversed. Changes that are committed in this way become adjustment layers in Photoshop for personal computers.
Basic tonal changes are made in the "adjust" section of Adobe's Project Rigel.
A vignetting tool lets you darken the corners of an image. You also can fiddle with the shape and color of the vignetting effect.
Project Rigel's healing options include spot healing, which is designed to quickly fix blemishes or clean up backgrounds; clone stamp, which lets you copy one patch of an image to a new area in the image; and correction of red-eye problems caused by camera flashes.
This screenshot of Project Rigel shows how cropping and rotating works on an iPhone.