C : Copy current image
V : Paste current image
Z : Undo
W : Go to parent
A : Go to left branch
D : Go to right branch
1...4 : Select colors
5...0 : Select brush sizes
+/- : Increase/decrease brush size
F : Go fullscreen
Drop me a line at analytic@gmail.com, tweet to @increpare, or post a bug report on GitHub.