Tutorial for Payway to integrate in iPhone app?

I want to use PayWay e-com to do transaction from my app. Since I am new to this technology, I am not sure where to start and how to integrate it in my iPhone app which has PHP backend.

Can anyone please suggest some good Tutorial to start with this? I found there are two ways to use it in our app.

1. PayWay Net

2. PayWay API

I want to work with second one i.e., PayWay API. Please suggest some good reference which will be useful in integrating to iOS app.