I think the Firefox extension might not work on mobile because it hooks into some undocumented addon apis to draw that translation bar UI. Those might not be available on mobile.

The translation code itself should work on mobile. It's just some javascript & wasm (albeit with SIMD instructions not implemented in Safari's WASM vm…)

I just installed the extension on Fenix Nightly and indeed, it does not work.

You can't download any addon for Firefox on iOS because it's almost Safari, only looking a bit different. All browsers on iOS has to use WebKit so FF is not really FF here on iOS.

I know, but I don't know what iOS webkit does and doesn't allow. Injecting code and responding to events in a way that makes the most important webextension APIs work _sounds_ like it should be possible (though it would take lots of work).

Sad to hear there's no such feature on iOS. At least Android gets uBlock Origin in the stable channels. Hopefully this will change when Apple will eventually be forced to permit other browsers into the iOS app store.

EU is after Apple in terms of Appstore - they want to force Apple to allow different stores. Then FF for iOS (the "real" one) could be distributed this way.