I love incorporating this into my classroom. It provides a great tool for the students to follow examples on their own TI 84 graphing calculator.
This is the android version of the TI-84. This is a great inexpensive tool for the students use instead of the graphing calculator.
Students love to use desmos. I like the feature that allows you to change the variable to a slider. This feature creates an opportunity for the students to discover how the parts of the formula affect the equation.