The Plex Media Streaming app for Windows Phone has been updated to version 188.8.131.52.
This update is mainly bug fixes and addresses and improves synching in the app.
The changelog reads:
(Sync) Library section filters/sorts/views not used for sync items
A number of user-reported crashes
The app is free but with limited functionality until an in-app purchase is made. Find the latest update of the Plex app in the Windows Phone Store here.