Groupon - Each day Groupon offers a deal through local vendors in your city.
Smartprix - Smartprix is an app by Smartpix.
idealo - Idealo is a free to use mobile application that helps you to find products, compare price and make an informed decision.
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.
Slickdeals.net - Slickdeals: The Best Deals, Coupons & Discounts on everything
Mobile Bandit - Don't Buy Deals get Mobile Bandit.