Plex has just renamed its desktop media player to Home Theater, adding 4K support. There's an improved user interface to boot, with the UI matching its various TV apps that will "leave all that original code behind".
The company hired the primary contributor from media playback engine 'mpv', as well as a full-time to help out with the redesigned app. Not only do we have a redesigned and faster UI, but there's support for a "true" 4K interface, multi-channel music tracks and better compatibility with H.265 video files, and more.
If you're a PlexPass subscriber, you can jump into this early, but if you're not - you'll be waiting a little while longer before you can get your hands on the 4K-capable Plex player.