First you need a HomeKit accessory, let’s start simple and buy a switch. For instance Eve Energy. This you can use for instance to turn on your Espresso machine. Next you need to add it to HomeKit, the database on your iPhone, remember? To add it you need an App.
There are a number of different apps available, but Apple already installed one on your phone: the Home app.
With the Home app you can add the accessory to HomeKit. You do this by scanning a code, normally a QR code on the device.
When the accessory is added to HomeKit is will be placed in a home. You can create a Home, or use an existing one. In HomeKit you can have multiple homes. This makes sense for instance when you have HomeKit accessories at home and at the office. Or your boat.
By just clicking the Espresso icon you can turn off the machine or on again. If you long-press the icon, you’ll be presented in details. Next if you click the little settings icon in the right bottom corner (or just swipe up) you’ll see the details of the accessory. If an accessory is favourite it will show up on the Home screen. See the image to the right.
So to summarise, if you call your Home ‘Home’ and use the switch to control your Espresso machine in the Kitchen you will see in the screen below in the Home App.