After the Plex app for Windows Phone received support recently for syncing content the company has now also added features which builds on this.
The app will now synchronize the playback position of synced content between your phone and desktop server and synced content can now be played and controlled on Plex players.
Most interesting however is the ability for the app to act as a mobile server, but unfortunately only for synced content.
Syncing does does however require a Plex Pass subscription, and its not hard to see that Plex is trying to move free users into becoming paying ones.
If you dont mind the subscription charge however, which is only $29.99 per year, the updated app can be found in the windows phone store here.