Just noticed it's available on Sonos Labs. Signed up for free trial, then applied promo code for full 60 day trial. Works great in iOS, Android, and can also login to their website: https://www.weyv.com/#/
When trying to authenticate via the Sonos app, though, it takes me to a different site on AWS, which doesn't recognize my login credentials, including my email address. Sent a note to their support team, letting Sonos know here, as well.