Looking for Alternatives to AirMusic for Streaming Audio to Sonos Speakers

I recently came across an app called AirMusic that allows you to stream audio to your speakers. I tested it with my new Sonos speaker, and it worked great,
This way I don’t need to create a Sonos account or share any privacy-sensitive information with them.

It’s also incredibly simple to use: you just open the app, connect with your wifi and select your speaker, and it connects instantly.

However, the downside is that the app requires a paid subscription.

Now, I’m wondering if there are any good alternatives out there that do the same thing, but without the cost.

Any recommendations would be appreciated!

is Sonos using some proprietary protocol? Is it not Wi-Fi or Bluetooth?

wifi indeed