Regarding drawing and CAD programs, have you heard of Moment of Inspiration (MoI)? The interface is designed to be suitable for stylus input with fewer and fatter buttons, scrubbing, etc. More importantly, the workflows also seem to be designed around this so repeating or chaining actions is easy and you never feel like stylus input is cramped or lacking precise control.
Other pros:
-fully customizable HTML UI
-fast, lightweight but powerful
-advanced actions (cloning along a path) aren't archaic hidden abilities for advanced users, they're discoverable and usable by new uers
-reasonable price
Cons:
-not as serious/enterprise as some people might need
-due to semi-indie status it probably won't serve as your ONLY 3d modeling tool with only a handful of file format option
All said, it makes for a fantastic addition to existing toolbelts but could also be a complete game changer for a certain class of users.