MyOpenMath creator here. Exciting to see a us mentioned, and glad it's working well for you. BTW, the open-source software that runs it is called IMathAS, and is on Github if anyone wants to contribute :)
Ah, bit of a late comment but I had no idea the creator of MOM was around HN. For the other section of the same class, different professor decided to use a paid software which is $120 + the paper back book needed is around $300 new. Trying to go through college when the softwares cost more than $/credit hour is pretty hard.