Desmos Online graphing tool, allows you to graph equations from simple to complex, overall awesome tool when you do not have a graphing calculator, and allows you to do stuff that a calculator would not!
Delta Math Delta Math is an online math assignment website that I plan to use in all of my classes when I begin to teach. It allows for several types of assignments, such as students needing to get 10 in a row before they get 100%, or every time the student gets one wrong, they need to answer 2 more questions correctly. This adds some flare to what can be dry assignments on websites like Castle Learning.