Bobulate: A contract of constraints.
"To produce something of merit, I adopt a kind of contract of constraints, an unspoken loose ruleset, that marks boundaries by which I must abide when I work."
It occurred to me while reading this, that maybe this is why I'm only drawing with physical pencils and paper now. Too much to fiddle with, or possibly the wrong UI.
Anyway, I love Bobulate. It's one of a few sites that I read every day in the browser, and so should you.