I've been turned onto this program for a few weeks now. I just adore it! It's so nice for loose sketching and general concepts. I've never really branched out and tried new things until I started fiddling around with this program. It caters so well to my frustration, as weird as that sounds. I'll get mad, scribble, and the nest thing I know I'm drawing because something appeared that caught my eye.
I will say I wish for an undo button, but I guess that just defeats the point of sketching, now doesn't it?
Here are a few things that I've sketched out in the program. I figure I need to at least try to update this.