What is Coupons at Checkout for iOS?
The app itself features nearby deals and a quick search utility to find coupons for online or in-store purchases.
The app also consists of an extension which can be used directly in Mobile Safari to find coupons while you're shopping, directly at checkout. Tapping on a code will automatically populate the coupon code box, and you can simple apply the code to your purchase.
The Coupons at Checkout for iOS mobile app is available from iTunes here.