The Google Shopping Content Objective-C Library by Google can access API data to sell products on Google, list ads, drive traffic, and increase sales. Developers can interact with the JSON API, working with iOS 3+ and Mac OS X 10.5+. Available introduction and example applications.
Based in Vancouver, BC, Payfirma has created an XML-based API that promises custom forms and full shopping carts to keep you in control of developing the flow of your credit card processing. The idea is to make business's lives simpler by reducing development costs with the Payfirma API that accepts Visa, Mastercard, Discover, and American Express among others.
Warranty Life launched for a single purpose:
"[develop] an easy-to-use system that takes the filing, searching and frustration out of keeping track of product warranties."
In its short existence, Warranty Life seems have to achieved its goal by improving warranty attachment rate to sales by 60% and its innovative system is now in use by hundreds of retailers across the US. Warranty Life wants to extend its reach and its value proposition by offering the Warranty API that can integrate with third party applications and websites.