Issues with version 2.1 or below
A recent update from Sonos caused issues in the app. This leads to miscommunication with the Sonos servers and does not allow to control your speakers. A new update is on the way to the App Store and can be downloaded as a free update soon. Please update to version 2.2 or newer (10/10/2019)
The App uses the official Sonos API to access your speakers. This is why you need to login with you Sonos Account that you have used for setting up your Sonos System. If you experience that the App is not listing your speakers make sure that you have used the correct account. You can check for the correct Account by opening the official Sonos App (on Mac/ iOS or Android) got to Settings -> Account Settings. The app will show you which is your account.
If you have a second or third Sonos system setup with the same account in a different location (like a weekend house) you can easily select it in the App by going into Settings-> Select household. It may take a while until all households are fetched.
The official Sonos Apps supports multiple Sonos Systems just by switching to a different WiFi Network. Unfortunately this feature is currently not supported by the Sonos API. If it will become availabe I will integrate it into the App
Special Icon features
With update V 2.1 I have integrated a new Icon for the Menu Bar.
You can deactivate the large icon and switch to a smaller icon in the settings. This will still allow you to play and pause with a right click, but not to change the volume.