The Payfirma Push Android SDK by Payfirma allows to integrate payments through API interaction. An example use case shows ACME as the invoicing application that intends to include credit card payments using the interface. Input and output variables display code associated to merchant's payment. For facilitation purposes, sample code presents a business transaction with a determined filter.
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.