Photoshop for the desktop is probably the biggest name in image-editing software, you can create all kinds of visual effects with it. Photoshop.com is a web-based image-hosting service that provides 2GB of free photo storage and plugs in to Facebook, Flickr, Photobucket and Picasa. You can upload photos, do basic editing, add captions and share the results right from your web browser.
Now you can do some of those things from your Android phone with the Photoshop.com Mobile app. You can create a Photoshop.com account or log in to an existing account. After you're set up, you can automatically upload every photo you take with your Android phone to your account, or download photos from your account. It's a useful way to back up and archive your photos without a lot of effort.
The app can also do some very basic photo-editing tasks, but if you go in expecting desktop-like Photoshop functionality, you will be sorely disappointed. You can crop, adjust brightness and saturation, and apply some not-very-exciting effects. You cannot rotate or resize photos, though, and video uploads and editing are not supported.
If you think of this app as a free, 2GB virtual storage card and not a photo-editing program, then you may be satisfied with it. The Photoshop brand, however, implies editing features that this app does not even begin to approach, and for that reason, I can't recommend it.