The app helps you annotate over your screen and teach/present better in your online classes.
The motivation behind the app was generated because of the need of screen annotation in programming/development classes. Explaining code directly while annotating is a big plus point and helps in explaining the concepts better.
This is an open source project and you can also contribute to make this app even better.
Follow the guide if you need help: https://www.tuffle.in/blog/tuffle-screen-annotator-guide