My favorite apps on F-Droid
NewPipe: a YouTube client, as mentioned in the thread, that allows you to play videos in the background, in a small popout over something else, adjust the playback speed, and also download videos for later. Great for lectures.<p>AdAway: it makes the ads go away by adjusting your hosts file (may require root) so it works both for in-app ads and web ads. I first installed it out of spite when Google failed my LineageOS on SafetyNet and blocked Android Pay even though it wasn't rooted but it made using the system so much more enjoyable I would now root it regardless.<p>FBReader: a pretty decent ebook reader although the complexity makes it feel like a 2006 Linux app.