For me, it's extensions on Firefox mobile (only about 14 are left out of thousands) and also the ability to right click on an image and click "View Image".
Privacy.<p>Silently opting users into ad telemetry data collection is pure evil and makes me sad to see, given how awesome and pro-indidual M used to be.
There's "Open Image in a New Tab" so "View Image" is not "really" gone: <a href="https://bugzilla.mozilla.org/show_bug.cgi?id=1690030" rel="nofollow">https://bugzilla.mozilla.org/show_bug.cgi?id=1690030</a>
- FTP<p>- Syndication feed (RSS/ATOM) "sniffer" (or whatever the hell it was called).<p>I know that's 2 things but I couldn't choose between the two in enough time.
The workaround for firefox extension is to use firefox developer version with addons collection.<p>Last I checked about:config did not work for me on stable android firefox .