Ask HN: Help building mac app with xcode

So I'm looking into building a Mac app similar to PhoneView (http://ecamm.com/mac/phoneview/quicktour.html?show=4) but I'm not sure how to go about it.

From my understanding there has to be a way to detect when the iPhone is plugged into the computer and pull the SMS information through a Mac app. How is PhoneView currently doing this?

Theres other sites but they require the phone to be jailbroken - yet phoneview has managed to do it without the phone being jailbroken

Any help is appreciated