Ask HN: What non-trivial JavaScript app would you like explained in depth?

I am preparing a course to teach developers how to create and maintain a non-trivial Javascript application. It will include in depth git history, discussions on architecture (why is it important to build feature X in way Y), annotated source code, and screencasts discussing sticky issues and giving insight into both the problem and solution.

My objective is to help those who know how to write javascript learn how to build production ready applications that accomplish a business goal. My hope is that this knowledge will increase confidence and productivity in the students' careers.

Is the app something you'd like to have a say about? Do you care which tools are used?

Disclaimer I will build on the shoulders on giants and as such the source code (including git history) will be released under as permissive a license as possible while following the licensing requirements of the chosen technologies; however -- some of the material will be created with the intention of making a profit.