I think the smart move for Mozilla would be a unified build process that exported FFos apps to iPhone and Android. If it were positioned as the best "write-once" hybrid web framework, FFos would gain a much larger app ecosystem as a by-product.

I don't know any popular app (Facebook, Spotify, Deezer, Play Music, Gmail, Pocket, ...) that uses such an hybrid framework. All the major apps have teams dedicated to each platform. They might share some code with a shared c++ library or J2objc (or a similar solution) but never a write-once ship everywhere app.

So that would only allow them to gain the low popularity/quality app. That's not really a win.

This happened a while ago, but hasn't seemed to catch on: https://github.com/mozilla/apk-factory-service

The issue is you need to have a pre-installed Firefox on the device. Too bad, such dependency can't be set in the manifests so it won't pull automatically from App Store or Google Play.