At the moment of writing this, Google has only a single touch enabled app in the Windows Store for Windows 8, 8.1 and RT users and that is Google Search. But there’s a simple way to run Google Docs as an app on Windows 8.
So, as I have mentioned above, the single true touch optimized Google app for Windows 8 devices and currently available on the Windows Store is Google Search. However, Google has recently updated its Chrome browser to allow it to launch in “Windows 8 mode”, which makes it feel more or less like a touch version would do. So, all you need to do is to open your Chrome browser on the desktop interface and then go the settings and then choose to launch Chrome in the Windows 8 modern user interface.
From there, you can choose to launch Google Docs and YouTubeas an “app” in the Windows 8 interface. As you can see in the above screenshot, it’s identical as the web app that you can access on docs.google.com, so the single app feature here is the fact that Chrome runs in the Modern user interface and allows you to switch between Google Docs, YouTube, Chrome or Gmail. All your favorite Google apps are now in a single location, as you can see in this screenshot from the right and it’s thus much easier to switch between all of them.
Thus, you can make use of the snapping features and launch Google Docs, YouTube or your Gmail account from a single app location in the Windows 8 touch interface. You can choose that panel with Google apps where you want. The real key to somehow mimicking the feel of a Windows 8 app per se is to run whichever app you want in full screen mode. Thus, especially on Windows 8 tablets, it will like it’s a standalone app.