Honey - Honey is a browser extension that automatically finds and applies coupon codes at checkout with a single click.
Wikibuy - Find lower prices at other sellers while you shop on Amazon
RetailMenot - The RetailMeNot mobile app allows you to find deals on the go for both online shopping and in store shopping.
CouponFollow Cently - Coupons at Checkout is a browser plugin for Chrome, Firefox, Internet Explorer, and Safari that...
CouponMate - Browser extension that automagically searches for coupons
Shopper.com - Uber for Coupon Codes