I wrote a course scheduler for students at my previous university. It doesn't have that many users, but I get a "thank you" every now and then, which is enough motivation for me to keep it updated. In any case, I automated the entire course data update process, so I only need to run a Python script before the start of each semester.

It's running on the Heroku free tier with a cheap domain, so it only costs me a few cups of coffee every year.

http://jadawil.xyz (sorry for the crappy design!)