If it were ported to Android/iOS, it'd need to adhere to the relevant standards from Google/Apple. If it did (and that's a hard task itself, see every other 'Google/Apple blocked my app' thread on HN) then it'd quickly be squashed by the other major competitors.

Can't have a non-monetised, FOSS, universal application available in the app stores! That's like ... that's like COMMUNISM, or something! /s