Hi i have been using touch for a good bit of my workflow. its a wonderful app for both ipad and iphone. now i am confused on the new additions. photo shop mix and sketch. are they replacing photo shop touch or they an upgrade of touch. i have noticed with touch you cant import layer files from a desktop psd into touch. how come?
AFAIK, there aren't any plans to supplant PS Touch with PS Mix. (At least I haven't heard anything.) It's still available for sale at Google Play; don't know about the App Store.
Mix seems a little hobbled compared to Touch. (e.g., Only 2 layers in Mix vs. 12 available in Touch.) While it's true that Mix can do things that Touch can't like Content-Aware Fill, it can't do more complex compositing. (See the sentence before.)
Since 12 layers is the max layers available in Touch, I think Touch flattening PSDs when imported was a failsafe mechanism. PSDs themselves can have theoretically thousands of layers. Also, Touch itself cannot support other types of layers like adjustment layers and layer masks. (Though you can fake an adjustment layer. Seek out Russell Brown's PS Touch tutorials on using "light layers" at adobe.tv for more info.)