Note that Plex currently requires a paid subscription (Plex Pass) for you to use their official app on the Nexus Player. Kodi/XBMC works good so far (a few bug reports on the Kodi Forums, but probably something they'll get resolved since it may be more of a Android 5.0 issue than a Nexus Player problem -- just guessing though)), and even shows up in the Main Menu of the Nexus Player.