Call forward application in iPhone

I want to make an app which forwards the call. Like you can see the app in app store already called "WorldOnGo" using VONAGE third party API. Can any one help me to kick off the app.

Thank you开发者_StackOverflow中文版 so much.

interesting.

I think you should differentiate between Internet calls (VoIP) & cellular calls first. VoIP calls can be redirected on server-side. However, calls via cellular network cannot be easily redirected as it involves service providers of cellular network. They won't let you mess up their infrastructure.