Jeff's book
Jeff also added a book.
https://tube.geogebra.org/b/1354727#
His comments
Here is my GeoGebra book "Calculus Stuff".I have added #13 "function of two variables" which I think is nice for graphing z=f(x,y) in a 3D Graphics window and shows level curves in the accompanying Graphics window. I might like it better if I could control the locations of those curves via a slider, and if they could appear on the function itself.I have also added #14, "Inverse Relation and Derivatives". My students often have trouble with this. I like this applet because it uses sliders to allow manipulation of the graphs in kind of an interesting way. I guess I just like sliders! The equations of the tangent lines to the given function and its derivative are printed but don't always stay on the screen when the graphs are manipulated, it should be simple to fix that. More challenging perhaps would be to display the equations in such a way that the relationship between the slope of the function and the slope of its derivative are more clearly displayed.