In addition to writing software for clients, I write some free software.
DBSchools Music Gradebook
Music Gradebook helps music teachers and their aides assess music students on their instruments and record and report on their progress through a book or series of books.
A Metronome, with various sounds, and a simple visualization.
Starting with the 2015–16 school year, Stanley Middle School (where I volunteer in the music department) uses block scheduling. Period Clock is a webapp that, during the school day, shows which period we are in, and how much time remains, as well as an accurate graphical display of the time periods.
Here is the music department’s period clock.
Talking Name Picker
A tool primarily for teachers to fairly and randomly call on students. Type or paste in a list of student names, and it will randomly choose them, and optionally speak each chosen name. I like to tell students not to raise their hands, then I ask a question, give them all a moment to think about it, then randomly choose a student to answer.
A tool primarily for teachers to ensure they spend equal amounts of time with all students in a group.