As a UX Designer, I'd say I've needed something like this: a true UI design app that only had the features I needed. None of Photoshop or Illustrator's extraneous features (with respect to a UI Designer's needs, anyway).
One thing that would definitely make me try it is a bundled/stock icon set that is well-integrated into the app. Finding open-license icons for my mockups (or drawing my own) is actually the most laborious part of my design process. If that was somehow shortened, or if I at least had inspiration built into my design tool, I'd be a happy camper.
One thing that would definitely make me try it is a bundled/stock icon set that is well-integrated into the app. Finding open-license icons for my mockups (or drawing my own) is actually the most laborious part of my design process. If that was somehow shortened, or if I at least had inspiration built into my design tool, I'd be a happy camper.