I built a Plex client that runs (almost) everywhere (macOS, Windows, Linux, iOS, Android) because I got tired of transcoding. It uses mpv, so it direct plays pretty much anything - HEVC, AV1, HDR, Dolby Vision, and ASS/SSA subtitles.You can download media for offline viewing, and do synchronized Watch Together sessions over WebRTC.
Built with Flutter, fully open source. Available on the App Store, Play Store, and GitHub with desktop binaries.