With this plugin you can create HomeKit speaker services for Volumio.

Speakers were introduced within the HomeKit protocol in iOS 10. However the Home App from Apple doesn't support controlling speakers. Even in current iOS 11 support was not added to the Home App. Though most third party HomeKit apps (I like the Example of Eve App) are able to control speakers. I'm guessing that speaker support will be included in the final iOS 11 release build or within the release of the HomePod.

First of all you should already have installed Homebridge on your device. Follow the instructions over at the HomeBridge Repo

To install the homebridge-volumio plugin simply run sudo npm install -g homebridge-volumio

Here is an example configuration. If you have several Volumio equipments, use the name parameter.

    "accessories": [
        {
            "accessory": "VOLUMIO",
            "name": "Volumio",
        }
    ]