The New York Times Register Java SDK allows developers to test In-App Billing of Google Play when building Android apps. Its documentation provides detailed procedures for installing and consuming the SDK.
Pactas, recurring billing solution provider, offers the Pactas API that allows developers to include Pactas functionality within third party apps and websites. Any need for recurring billing (e.g. carsharing, music flatrates, cloud services, etc.) can be simplified and streamlined with the Pactas solution. Pactas enables users to manage subscriptions, track payments, and map pricing. Access to the platform can customize to each users' situation depending on need, resources, and integration opportunities.