I am building an IoT messaging platform that will allow devices all over the world to communicate easily and quickly among themselves just like IM messaging networks for people. I'm building it and testing it on my Raspberry Pi Windows IoT device. Your devices can use the service using AMQP or HTTP. Is this something you will find useful? Let me know if you're interested in being one of the first people to use this service when it is ready for beta testing.
Thanks!
Miguel