iPhone sdk call interception

We are developing a app .The function of the app is "when we got a call automatically we have to reply thro开发者_StackOverflow中文版ugh text/voice message .So,can you tell us whether it possible in iPhone.If means guide us to build the app.

Thanks in advance ,

BrightRaj

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It is not possible to access the phone in such a way with the current SDK. I guess it can be done on a jailbroken iPhone or on the Android platform.