Our app WebCode (http://www.webcodeapp.com) is a vector drawing app that instantly generates HTML5 Canvas code. No need to write all of it by hand :-)
I just bought it a week ago. It makes canvas a lot more human. I've used it to create a few minor UI elements even, but main issue I've had simply the lack of rotate (or my ability to find it).
Still, its best tool I've used for Canvas.
Also, we'll make rotations much more useful in future updates.