Plex is a media management software that doubles as a free streaming service. Its main function is to organize your own library of content—that is, your own video, photo, or sound files—and make it streamable alongside Plex's offerings of 200+ live TV channels and 50,000+ on-demand movies and shows. Plex's basic package comes at no cost, but it also has a premium package starting at $4.99/month that boasts additional features, such as the ability to download content and watch them offline, among other things.