The USAePay iOS Library provides an interface for running server to server processing. The Library is for developing websites using the client side method, which provides a stable UI. This library is written in Objective-C.
SumUp, a mobile payments rising star, recently announced an API that allows third party apps to accept credit card and cash payments without leaving the app. Prior to the API, SumUp users and customers were required to use the SumUp app in isolation from the merchant app to utilize the slick mobile payments platform.
Moving money online is commonplace these days, and the simpler and faster the process can be, the more appealing it is. Ripple provides another option in the world of online payment solutions. It's an open source, almost free to use payment network that provides a simple and hassle-free way for anyone in the world to send money to anyone else. The Ripple API allows developers to use this functionality and integrate the payment system into other projects.