One of the most notable differences between the tablet interface and the phone interface -- aside from the necessary rearrangement of the tools -- is the switch to a less interactive and somewhat insufficient help system. There are only five topics with only the briefest of instruction, and nowhere does it tell you what each tool does. While most people familiar with image-editing tools and techniques will probably quickly pick up the app's operation, certain things might still elude you. For instance, after making selections with the Scribble Selection tool (), where you doodle over what to keep and what to delete, not everyone will know to then go to the selection menu and look for Extract. Instead, they'll probably do what I did: choose Cut. But Cut doesn't understand the scribbled Keep and Remove areas, and actually deletes the inverse of what you've selected.
I also find the traditional "marching ants" type of selection display completely unsuited to phone-size screens. In places it's impossible to make out the border, requiring a lot of tedious zooming in and out to tweak the selection. It's easier to see if you go into Refine Edge, which overlays a red mask, but overall I think we need a new interface metaphor for handling selections on small screens.
Furthermore, a lot of the things missing from the tablet version are still missing or insufficient. Like one-click white balance. There's a temperature slider, at least, but it doesn't preview in real-enough time, and there's no visual (for example, red to blue) or Kelvin reference -- what the heck is a -2 percent change in color temperature? Is that warmer or cooler? This is UI design 101, folks.
And working with text is annoying. You can enter, place, resize, and rotate text using one of the handful of included fonts. But once you click apply, it rasterizes the text. And the bundled fonts? A crime against typography. Given that Adobe possesses a type foundry and decades of type-rendering experience, you'd think we'd get something better than display faces like Cottonwood and Mesquite, and otherwise nice body faces that are totally unsuited to most of what you'd be doing with the app. Plus, given the audience for the product -- advanced users -- I'm surprised there's no quick watermarking tool.
While I understand the necessity of drawing a line in the operating-system sand, the fact that Photoshop Touch operates only on Android 4.0 or higher is a bit of a disappointment, since as of this writing only roughly half of users are running a compatible version (very roughly, since the reported numbers are for all devices, not just phones). On the Apple side, it requires iOS 5 or later, plus an iPhone 4S/fifth-generation iPod Touch or newer.
It's a full-featured image-editing app, with modern selection tools, brushes, adjustments, effects, warps, and gradients. And though it seems nitpicky to complain about such things for what's a very neat technological achievement, Adobe's charging you $4.99 per device, on top of any subscription fees you're probably already paying for Creative Cloud. Yes, the app is cool and useful, but the interface still needs some work.