They are not too hard to find. I would use this one as a starting point: https://github.com/neomjs/neo/tree/dev/docs/app/view (since the docs app UI is written using neo.mjs).

On the repo you have an apps folder (RW2 is a better example) as well as an examples folder.

If you open the online examples => docs app, you can view into the code for all classes. If you use the docs app version with the Chrome flag, all available examples are included.