Google's promising that you can read the ebooks via the iOS, Android, and Chrome apps, but I'm still awaiting confirmation that they are available in France. If the apps aren't up yet then French readers can still head to Google Play Books and start browsing and buying books. And of course you can always find the Google Play books app on sites like Freeware Lovers, where it is a free download.
This makes a total of 5 European countries with access to the Google eBookstore (Germany, France, Italy, Spain, UK). If you add in Canada, Australia, and the US, the total population covered by the Google eBookstore is still rather tiny when compared to the markets served by Amazon, Kobo, or even iBooks.