AliPrice - AliExpress Price Tracker app lets you track the price history of any item from many online retailers like AliExpress, Daraz, and Amazon, etc.
Price Tracker for Amazon - Price Tracker for Amazon is a shopping app that allows you to browse for favorite products from famous online stores know as Amazon for a better price.
idealo - Idealo is a free to use mobile application that helps you to find products, compare price and make an informed decision.
Smartprix - Smartprix is an app by Smartpix.
Camelcamelcamel - Easily monitor Amazon product prices and get alerts when they drop.
Tripadvisor - The Tripadvisor mobile app is available for the Android and iOS platforms. It can be used to create reviews of hotels, restaurants, and to chat with other travelers on Tripadvisor forums.