The Authorize.net Ruby SDK by Authorize.net allows communication with the API to implement authorization features into applications, specifically beneficial to verify payments with credit cards. Three steps show how install the SDK, create a Ruby file for a new transaction, and run the program.
Payleven, the Square equivalent for the world outside of the US, has launched an API to complement its mobile payment device. Prior to the API, use of Payleven's mobile payment device required downloading the Payleven app (similar to Square's current model). However, the API allows developers to integrate Payleven's functionality within third party apps.