I know a lot of engineering students that use this app, but have to use many other apps as well to take coding, circuit or higher level math classes. I use https://www.stempad.com/editor but would rather use GoodNotes6 because of all your other great features. The code and circuit block don't even need to be functional, just formatted like code and maybe helps you code like VS Code based on the language. It just takes a lot of time going back and forth between apps.