My spouse is a teacher. The science department at the school uses a relatively complicated grading mechanism called conjunctive standards based grading, which used to require a lot of spreadsheet magic to work. I wrote a gradebook app (firebase, angular) that handles the grade entry (not grading), conversion of assessment data into grade reports for students, plus charting and stuff so you can see student or course aggregate progress over time.

I originally thought more people might use it, but I have basically 6 teachers.