In my opinion Paint is one of the best ever examples of good software UI & UX. It's so simple and obvious how to use it - all the most important controls are r

In my opinion Paint is one of the best ever examples of good software UI & UX. It's so simple and obvious how to use it - all the most important controls are right there to hand and the few slightly more advanced features are easily discoverable in a well organised, fairly flat menu system. You can literally figure out every function either by intuition or very quick trial and error. It uses skeuomorphism and icons wonderfully to make everything absolutely clear in form and function, even for a very novice user. And - I think this is an important - it deals with images as a 2D grid of pixels without any abstractions on top. No semi-3D overlapping 'layers', etc. In keeping it simple, they give the user maximum control over the image with no abstractions to get in the way. In all sincerity, I think it should be a case study in simple, right-tool-for-the-job UX and UI design.