RetailMenot - The RetailMeNot mobile app allows you to find deals on the go for both online shopping and in store shopping.
ebates - Find thousands of coupons, promo codes and discounts.
Slickdeals.net - Slickdeals: The Best Deals, Coupons & Discounts on everything
link-o-mat - Cashback Portal - Verdiene mit linkomat Cashback - weltweit über 9500 Shops
idealo - Idealo is a free to use mobile application that helps you to find products, compare price and make an informed decision.
Shoop - Interactive ticketing and social networking platform. Book social encounters, not just tickets.