Press left/right arrow to increase the pen size, also press like and favorite. That is an order, children. And be sure to give the amaazziiinnnnggggg GRROOOOOVVVVVYYYY4 a follow!
I made a few tweaks, now you can manually change the shade, up arrow for lighter, and down arrow for darker. And left arrow to make the size smaller, right arrow for bigger. I also changed the position of the pencil in co-relation to the mouse. Sooooo without further ado, have fun and SCRATCH ON!!!!!!