Developing SMS Application

Hi All,

I'm interested in developing an SMS iphone application for ios 4 that reads SMS and auto replies them.

There are a few different solutions out there such as:

1.Sending sms with the CoreTelephony and private frameworks


2. Using the iphone's modem

And so far does not work maybe because these projects were done with the ios 3 and below.

However, to my knowledge it is possible because there are jail broken apps suchs as:

http://www.iphonespyapp.com

which can read and forward smses.

Can somebody point me to the right direction?

Your expertise is greatly appreciated :)