The Google Home app is used to set up and manage Chromecast, Google Home, and other smart devices compatible with Google Home. While it's designed to only work with iOS and Android devices, there are workarounds for using the Google Home app on PC.
You can install an Android emulator for Windows to run Android apps on your PC. For example, Bluestacks is an Android emulator that allows you to install and run several Android applications, including the Google Home app. The overall functionality will be similar, but there's some extra work required to get the emulator set up.
Google Chrome can mimic some of the functionality of the Google Home app, but it's very limited. For example, you cannot set up Google Home devices using the Chrome browser, so you still need a mobile device or Android emulator for that. You can, however, cast or stream to any of your Google Home or Chromecast devices. Before you begin, make sure you are running the latest version of Chrome and that your PC and Google Home device are connected to the same Wi-Fi network. To cast or stream to a Google Home device, select the three vertical dots in the top-right corner of Chrome and choose Cast, then select your device.
Google Home functionality depends on the method you're using. When using an emulator, you'll have full access to all features. However, when using only your browser, there are certain things you won't be able to do, such as setting up devices for the first time. It is also possible to install Google Assistant on Windows to take full advantage of Google's virtual assistant; however, voice support is rather limited when streaming media from Chrome to Google Home devices, so you can only use a few simple commands such as "Stop" and "Max volume."