Link: https://www.xda-developers.com/this-open-source-plex-client-now-lets-you-watch-media-with-friends/

Back in my day, if you wanted to watch something with a friend remotely, you both had to load it up on your PCs and then do a "3-2-1 play" countdown to ensure you were both seeing the same thing at the same time. Fortunately, tech companies have since respected that people ideally want the app to do the syncing for them, and as such, there are plenty of ways to watch things with your friends with minimal hassle.

Plex is no different. It has a "Watch Together" feature that lets you open up a digital room to invite people into. Once everyone's settled and has their popcorn, you hit the play button on your end, and it'll sync your progress with everyone in the room. Now, an open-source version of Plex has added Watch Together compatibility to its repertoire, which is great news for people who like to know what their apps are doing under the hood.

Just downloaded their APK to try out from their website.

Seems pretty good. I like that it can use both Plex and Jellyfin. I have instances running so it's kind of cool to be able to use either.

Also you can pick where you want downloaded content to go. And I am able to pick my SD card I have on my tablet.

So to me it's a winner.