Mozilla has quite a few Firefox browsers for Android, each catering to a certain market or use case. Firefox Lite is primarily intended for India and other Asian countries, with a minimal app size and various tie-ins with news and shopping services. However, it has never quite worked in landscape mode — until a recent update, anyway.
Firefox Lite 2.1.18 was a minor update, but it did include one key change: the address bar no longer vanishes when you flip your phone to horizontal mode, as it did before. You can now manage tabs, change the web address, go home, and perform other actions without going back to portrait mode — something that both Firefox and Firefox Preview could already do.
Left: Old UI; Right: New UI
The New Tab Page still kicks the browser back into portrait mode, so there's still some work to be done, but the changes are welcome improvements. Firefox Lite isn't available on the Play Store in the US and some other regions, so if you want to give it a try, download the APK from APKMirror.