I got to thinking about the fat, dumb, stinky, zit-faced, slack-jawed, high school drop-out Cashier kid today. The POS interface is pretty self-explanatory and colorful already, but I added some fast little animations today so that his eyes can follow along and better understand what he needs to tap on next. I have to assume that some merchants will never bother to train their employees. Material design is freakin awesome, lovin this stuff :)