Pinch-to-zoom should work on an iPad Pro on Safari. PhotoStructure will automatically replace the preview image with the full-size original image as you zoom in, so it shouldn’t be blurry (or at least more blurry than the original image)
The zoom widget in the header hides itself on browsers that have touchscreens (with the hope that people will be more used to pinch-zoom gestures on those devices).
If this isn’t what you’re seeing, holler: I wouldn’t be surprised if Apple did some shenanigans with Safari user agents on iPad Pros.
YEAH, that bit is definitely janky. I should be able to hook into pinch gesture events and handle zoom just like I do with shift-mousewheel: so the image would zoom, but the top bar would stay where it is. I’ll change this to a feature request to improve zoom UX.
I’m a new user of PS and would also like to request a swipe action be added to change to the next picture. I have a daughter with special needs who loves PS…the random presentation is perfect for her. It would, however, be helpful to be able to swipe to the next picture (in addition to using the arrow).