How I Use It
I teach Graphic Design, but this would be applicable to any class that studies color theory. Not only does it introduce and reinforce relationships between colors (old school: complementary, analogous, etc.), but it allows students to capture color palettes from the world around them and convert the colors to RGB, CMYK, and hexadecimal values (new school). This ties in especially well if the students will be using Adobe's Software.
This tool is a great asset in teaching Graphic Design. Although signing up for an account is free, it is annoying that you must make (or have) an account first in order to use it. Creating the account, moves it to the 5-15 minute range of set-up when it should really be less than 5 miuntes.