READ ALL INSTRUCTIONS BELOW: At he beginning of the program, you can either input the coordinates of the two points you want to find the slope of (click T), or click on there coordinates on the coordinate plane. To zoom in or out on the coordinate plane, press the up and down arrows (There are 30 units between each line for the coordinate plane that is more zoomed in, and 20 for the other coordinate plane). Press space to enter a new calculation.
Thanks to FinitePlane for the music. Comment, "Slope is dope!" if you see this.