The app is up for grabs now from Apple's App Store and Google Play for £2.99. You'll need an iPhone 4S or later, or fifth generation iPod touch, running at least iOS 5, or an Android smartie powered by Android 4.0 Ice Cream Sandwich or later. There are no plans for a Windows Phone 8 version at the moment.
Photoshop Touch made its debut for tablets back in October 2011, so it's taken some time for Adobe to cram it onto the smaller screen. The mobile version has exactly the same features as that for tablets, so you get layers, selection tools, filters, tonal and colour adjustments, effects, and the ability to add graphical text. It'll let you edit images as large as 12 megapixels with layers, so you might have to shrink down anything taken with a 13-megapixel camera, like that on the Sony Xperia Z.
You can combine images using the Scribble Selection feature, and back them up in the cloud thanks to 2GB of free storage from Adobe.
Is there anything different from the tablet version? Well, the interface has changed to accommodate the smaller screen. (Though where that leaves the Asus Fonepad, I've no idea.) The tutorials are less interactive as well, being more of a guide to get you started. The tablet version is also notably pricier: £6.99 for both the iOS and Android version. Though it probably will be easier to use, thanks to the bigger screen.
For a full overview, check out Adobe's handy guide.
Adobe has been criticised for its pricey desktop software in the past, but what do you think of its apps? Are there better alternatives out there? And should it have launched the mobile version sooner? Let me know in the comments, or on our Facebook page.