The Hiveage PHP SDK by Lance Pioch interacts with the API to access billing features. Installation and usage available. Hiveage aims to help freelancers in over 140 countries to facilitate invoicing processes with their clients.
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.
Billaway, a rewards program solutions provider for enterprises, has just announced the launch of the Billaway API which allows developers to integrate the Billaway platform into existing billpay and other product purchase systems.