having fun but offer three ideas

three ideas: 1) a square eraser tool. 2) the ability to undo just your last erase (for accidental touches) 3) the ability to erase all of one color from a layer. ex. use a dropper - pick a color.

cool app I'm having fun with it. the layers stop after 4 right? maybe the ability to add more layers would be nice? last question, what does the erase thing do on the erase screen. pencil, brush, eraser that I can't quite figure out. thanks