How I Use It
FooPlot is a free online graphing utility that is fairly easy to use.
It is relatively simple to enter basic functions and see the graphs. Also the basic controls allowing you to assign specific colors and see points and intersections are helpful. The other main "pro" is that the graphs created are not subject to copyright and can be freely used to create worksheets, lessons, presentations etc. without having to worry about copyright violation.
While simple to use, it is definitely lacking some of the more advanced features of other graphing utilities that are available. For example, I often use the "slider" feature available in other tools to help support student exploration and inquiry and this is not available in FooPlot.
Overall, FooPlot is a free and simple resource that would enable one to create good quality, copyright free graphics to embed in worksheets, lessons or websites. For use in a class activities, I would likely turn to other utilities that offer more functionality and real time interaction for students.