@Nedks TL;DR the Windows build doesn't work and needs to be updated.

From ios9 forward there was a change that caused Airsonos sources not to show up. This was fixed in the main build, but the Windows build was never updated. I pinged @stephen in a separate issue on this, but have not heard back. There haven't been any updates to this project in a while so I'm not sure he is still working on it. If someone knows how to create a Windows build like was done previously, I'd be willing to try. I have an RPi Zero but haven't bothered with Airsonos on it because it's my Homebridge server and I don't want to risk bringing it down (plus I think the Zero won't have good enough performance for it).

Same issue as #390.

@Nedks I ran across a similar application made (and being maintained) by @philippe44, AirConnect. The README is really good and has a few tweaks you need to make to run on Sonos. The only drawback is that you have to introduce a buffering delay for it to work reliably, so you can't use multi-room through iTunes as you're going to have about a 3 second delay between sources.