RetailMenot - The RetailMeNot mobile app allows you to find deals on the go for both online shopping and in store shopping.

AliPrice - AliExpress Price Tracker app lets you track the price history of any item from many online retailers like AliExpress, Daraz, and Amazon, etc.

Slickdeals.net - Slickdeals: The Best Deals, Coupons & Discounts on everything

idealo - Idealo is a free to use mobile application that helps you to find products, compare price and make an informed decision.

Rakuten - Feel the Joy of Cash Back. Find coupons and Cash Back in just 1 click with the Rakuten browser extension

Camelcamelcamel - Easily monitor Amazon product prices and get alerts when they drop.