All it does is provide a REST API for an existing open source library. That's written on the home page. You can use the existing open source library (if you're

All it does is provide a REST API for an existing open source library. That's written on the home page. You can use the existing open source library (if you're using PHP). But then you have to keep it updated. The API does that for you - as well as allowing you to use it from any language.