If you’ve read this book cover to cover, you now know that it was designed to get you up and running with a broad array of popular PayPal products and a common technology set based upon GAE and Python. Although PayPal’s Mobile Payment Libraries (MPLs)—which allow you to create in-app purchases for iOS, Android, and BlackBerry—don’t fit the given scope and focus of the book because they require specialized development environments such as Eclipse and XCode as well as additional programming languages such as Java and Objective-C, you should definitely know that MPLs exist and what they can do to help you be successful in your commerce strategy. This brief appendix merely attempts to provide a shallow orientation and point you to some valuable resources online that can help you get up and running with MPLs. Entire books could be written on learning iOS and Objective-C, for example, with an underlying theme of using the corresponding MPL to implement an application involving mobile commerce.
In short, an application that employs MPLs allows you to embed a “Pay with PayPal” button natively within the iOS, Android, or BlackBerry application you’re developing and provides you with an easy-to-use software development kit (SDK) that provides views for logging users into their PayPal accounts and processing payments. With regard to implementation details, there truly is minimal hassle involved in integrating MPLs into an existing app, and in many circumstances, there can be less work involved in integrating an MPL into a native mobile application than in integrating a product like Express Checkout into an existing web application.