Paribus:

This holiday season American consumers are expected to lose tens of millions in unclaimed refunds from online retailers. But a popular new smartphone app called Paribus is solving this problem for two million consumers. Paribus automatically scans your online shopping receipts for price drops and shipping delays, quickly files a digital claim with the retailer, and instantly deposits your refund back to your credit card. It's free and requires absolutely zero effort.

So far, Paribus has identified over $6.5 million dollars in refunds for 2 million consumers, with millions more expected this holiday season.
 

eBates:

The app and website bring all the weekly ads into one place so you can see the doorbuster from Walmart, Best Buy, and Target together. Plus, search for a product keyword (ex. television) and the app will pull in all of the qualifying deals from the ads so you don't have to waste time flipping through them. Shop where you already like to shop, but get cash back after your purchases, whether you opt to pay by check or a PayPal deposit.

The percentage varies depending on the online retailer or marketplace, and there are more than 2,000 to choose from, including Amazon, Walmart, Macy’s, Target, eBay, Kohl’s, Best Buy, American Eagle.

Here is a little gift from me to you from eBates! $25

https://www.ebates.com/r/JESSIC75573?eeid=28187

Flipp:

This app helps you find the best deals in stores by aggregating all your local (flyers) in one place. Instead of searching multiple websites and stores it lets you browse coupons so you can virtually clip coupons. There's a smart shopping list section that will automatically show you who has the best deals around you.