Question about Google Home

The app for this is available in the Google Play Store? If so, which one is it?

I wonder if you can put the language in French or not?
or if it is only in German

In German. But German (Germany) and not German (Switzerland). There are very small things like available services.
But you can change the language if a Swiss variant is available. You have to address the thing in High German anyway, and a little accent is no problem.