This is a great App and I just wanted to help out with a small observation.
I'm a digital artist and I use a Wacom tablet for drawing digitally.
I noticed (running on an iMac) that there is a small, roughly 0.2
second delay on the time between the wacom pen stroke pressure
and the application of pixels in all the brushes.
Basically, when you draw, the line is appearing late. It makes it very
hard to sketch anything in detail.
I have the brush width settings very low, in order to mimic a real pencil
width.
I love the paint blend tool, a great feature, and 'paint select' is excellent,
a great idea.
My best,
Ed