I create a lot of different Mathematica modules for my various courses. In the pull-down menu above, you can investigate some of the ones I’ve cobbled together by general class area. Feel free to use these in any of your classes and leave a comment to tell me what you think, or if you’ve discovered an error.
(Also … when I was first learning how to make modules, I got a lot of subject ideas and techniques for getting out of programming jams from Mathematica’s Demonstrations site. I’ve tried to be very good about citing in this regard, but if you find one and think, “Hey! That’s mine,” by all means, let me know so I can cite your work properly.)