The video streaming application Plex has been made available on the Sony app store, and is compatible with the PlayStation 3 and the PlayStation 4. There are no plans to support PlayStation Vita or PlayStation TV.
Plex allows users to maintain their own personal collection of video files on a home server and stream that video to multiple devices in their home. This includes iOS, Android, Macintosh and Windows PC platforms as well as devices like Chromecast, Fire TV, Roku and Vizio televisions. Users have been clamoring for a PlayStation option for some time, and starting today Plex is rolling their new application out worldwide.
In a blog post published today Plex stated that it actually began work on the PlayStation app before the Xbox One app. Only now is it complete, and has been released by Sony in Europe and "most of" Asia. The app is scheduled for release in the U.S. "soon" says the post. A complete listing of platforms and countries is updated by Plex here.