They did :) A lot of their tools can be found on their github profile. Its insane to think this was 24 years ago. I still remember seeing fr-08 at had my mind blown. Seeing the credits across the screen after 5 minutes saying "oh hey we still have 7 kb left so heres a bunch of text" :D And that text went on for another 5 minutes until it finally looped.
You can install all kinds of extensions on Firefox on Android my friend. Firefox for Android is one of the killer apps now IMHO. Termux, Tasker, KDE Connect, and NetGuard are some others.