PriceCute - Keep up with your competition's pricing on Amazon
Onboarded - User Onboarding as a Service
Pricy - Amazon price watch
RetailMenot - The RetailMeNot mobile app allows you to find deals on the go for both online shopping and in store shopping.
Camelcamelcamel - Easily monitor Amazon product prices and get alerts when they drop.
Cartercoupons.com - Coupons Promo Codes Extreme Couponing CarterCoupons.com