iPhone app with call features

Question

I'm trying to get into a new project, by creating an iOS application. But before I start I would like to understand some points:

• is it possible to let an application make a phone call? So what I mean is, assumed we have a phone number and would like to call it. Would it be possible to use an (my) application to call this number?

• is it possible to let an application speak during a phone call? So after the application started the call, would it be possible that some predefined statements are said in the call?

• is it possible that this application hears, registers and analyses what the other person on the phone line is saying? (Leaving apart the privacy issue, assuming that the other person is willing to do that).

Could you please help me? If my question aren't clear, please tell me, I will try to explain it in another way.

Many Thanks

FP

Answer 1

iOS is very restricted in terms of the system behaviors third party applications can influence.

To answer your question bluntly, a third party application could prompt the user to initiate a phone / FaceTime call. Once the call is initiated however, your app would enter a background state and relinquish control to the system. The app would not be able to contribute or read any data related to the system phone / FaceTime call.

iOS 10 introduces a VoIP extension, CallKit , which allows third party apps to use the built in calling UI with a custom protocol. You could implement your own protocol (and host servers for handling the exchange of information) and build an extension to make it feel like a system call. You'd be responsible for all aspects of the custom call protocol and thus reading voices, contributing audio, etc. would all be possible (and up to your implementation).

Outside of iOS 10, you would have to built your own VoIP system and interface entirely from scratch.

For more info on CallKit :

WWDC Enhancing VoIP Apps with CallKit

CallKit Enabled Sample App