Here is a screen shot of Desmos. This was taken from Desmos.com. I use Desmos to create graphs that I can use on tests or project on the Smartboard. These graphs have gridlines which makes it easier for students to read compared to a TI-84 emulator for Smartboard. In addition, Desmos has some activities that students can do collaboratively. This year, I hope to explore one or two of these activities. This website is geared to high school students. Let me know if there are any questions.