Building a tool for offline coding practice on flights/trips — would you actually use this?

Hey everyone,

I'm a developer working on a side project/startup idea and wanted to get honest feedback before I sink more time into it.

The idea: a website where you pick a programming language and a specific track (e.g., Go basics, or backend development with Go), and it generates a downloadable offline package — documentation, tutorials, and exercises — packed into a zip file. You download it before you lose internet access (long flight, train, remote area, wherever), and once offline you just open it in your browser like a normal site. No connection needed.

I know there are already tools like DevDocs, Dash, and Zeal that let you save documentation offline. What I'm trying to do differently is focus on structured learning tracks with exercises, not just a raw doc viewer — more like a self-contained mini-course you can work through with zero connectivity.

I'm trying to figure out monetization without doing a subscription (that already feels like the wrong model for something people might use a handful of times a year). Current thinking is one-time purchase per track, or eventually partnering with airlines.

Genuine questions for you all:

1. Would you pay a small one-time fee for something like this? (like 5 dollars)
2. Would you use it even if it were free — or does existing offline documentation (Dash, DevDocs, etc.) already solve this well enough for you?

Trying not to build something nobody wants, so brutally honest feedback is welcome. Thanks!

https://redd.it/1utrasf
@r_cpp