Hello,
During the last month or so I've been developing an app that lets you stream whatever you are playing on your computer to your Sonos devices. There is a delay so the app isn’t that suitable for movies, Skype calls. The main use case is to enable music not otherwise provided in the official app, e.g. live concerts on YouTube, Twitch and what not.
The app is open source and completely free. You can download the app for Windows 10 at budgiestream.com
I would love to hear feedback on the app