AliPrice - AliExpress Price Tracker app lets you track the price history of any item from many online retailers like AliExpress, Daraz, and Amazon, etc.
Gift Hero - The best wish list ever
idealo - Idealo is a free to use mobile application that helps you to find products, compare price and make an informed decision.
Coupofy - Coupofy is USAs number 1 trustworthy deals and coupons website.
Camelcamelcamel - Easily monitor Amazon product prices and get alerts when they drop.
LoveSales - Find and save products you love, get alerted when they go on sale.