Part of the The Realtime® Framework, Realtime Cloud Messaging (aka ORTC) is a secure, fast and highly scalable cloud-hosted Pub/Sub real-time message broker for web and mobile apps.
If you're building a Windows Universal App with data that needs to be updated in the user’s interface as it changes (e.g. real-time stock quotes or ever changing social news feed) Realtime Cloud Messaging is the reliable, easy, unbelievably fast, “works everywhere” solution.
https://www.nuget.org/packages/RealtimeFramework.Messaging/
PM> Install-Package RealtimeFramework.Messaging
http://messaging-public.realtime.co/documentation/windows8.1/2.1.0/index.html
Source code of a simple UWP chat using this Realtime SDK: https://github.com/realtime-framework/UWP-SpokenChat
Realtime.co