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.