Plex is a free media server add-on for many devices, including Chromecast, Xbox, Playstation, Apple devices, Roku, Fire TV, and more.
Ranked in these QuestionsQuestion Ranking
Pro Supported on many devices
It's pretty hard to find a NAS or STB that doesn't support Plex.
Pro Added lots of media databases
Metadata for media files will automatically be updated by using media databases. This provides posters, movie trailers, descriptions, information about actors, etc.
Pro Accessible via web browser
A modern web browser is enough to get everything Plex has to offer.
Con Needs registration
You need a PLEX account even if you use it on your local LAN.
Con No gapless audio-0layback
Plex still does not support gapless playback of audio files such as mp3 or FLAC.