Before flights with patchy/no wifi, I often download a long, single-page tutorial. This is perfect. Curious if anyone knows of any for other languages/tech (e.g. beyond SQL).
A failed attempt was to load (very) many (e.g. about 100) pages of javascript lessons from w3schools before the plane took off, but for some reason the pages tried to refresh during the flight and I lost them all, so that was a massive waste of time (opening them all before the flight took about 20 minutes).
https://cryptopals.com/ (a remake of the Matasano crypto challenges) understand crypto by actually building and then subsequently breaking it (it's not strictly single-page, but wget can mirror it nicely)