We are also changing how remote playback works for streaming personal media (that is, playback when not on the same local network as the server). The reality is that we need more resources to continue putting forth the best personal media experience, and as a result, we will no longer offer remote playback as a free feature. This—alongside the new Plex Pass pricing—will help provide those resources. This change will apply to the future release of our new Plex experience for mobile and other platforms.
Soon(tm) it'll be on the store. Having to build and push to tizen is the absolute worst part of jellyfin (if you have to) otherwise there's clients for every platform - even LG's webOS.
There's also finamp for music specific playback, so jellyfin can pretty much do everything
However as stated further down the article, it's easier to just use a web browser and access your jellyfin server that way. Login, bookmark the URL (don't forget to include the port) and then hit full screen.
Note: You may need to tweak (server side) your transcoding and subtitle settings.