Google Offers is no way near Groupon but it is slowly expanding to a number of cities in the US, hopefully it will go worldwide soon after.
This extension not only shows Google Offers near your area but also offers from Gilt City, kgbdeals and zozi according to Google Blog.
Maybe they will open source it for others like Groupon, Amazon Local Deals etc., to share their deals in the near future.
Once you find a deal, you can either view it and buy it or share it with your Google+, Facebook and Twitter friends.
You can install it for your Chrome browser from this Chrome Webstore link.
If you want to add your offers in Google Offers visit, http://www.google.com/offers/business/.