Hey Zach. Cool app! Thank you for open sourcing the project.
As the project currently lack technical documentation, I did a quick review of the source code and here’s some of my findings:
- this is a fully JavaScript front-end web app
- core technologies used to built this app:
- React.js
- modern JavaScript (ES6)
- Create React App (CRA)
- CRA is a tool based on WebPack for compiling and packaging web assets such as static HTML, CSS, images, etc
- UI styled using plain CSS (no Bootstrap or 3rd-party CSS framework dependency, which is nice)
The kind of web stack I used a lot in my work.
Questions:
- Where can I find these lesson transcript files:
assets/dl-1-1/transcript.json?
- The auto-generated transcripts are pretty bad. If anyone wants to share a better one, I can update it.
How did you generate these? I suggest you take a look at:
- Hiromi’s detailed notes and it’s time-coded to sync with the lesson video
- melonkernel’s captions work that links to different parts in video
Thank you for starting this project. You just turn some idea I had at the back of my head into reality 
I was looking for a better way to watch the lesson video together with the transcripts side-by-side when I am in the deep study mode. Sort of like Coursera video player. If I have a bit of free time, I will contribute to this project. No promise though.