Can an iPhone app be opened when the iPhone rings or change it's state when the iPhone rings?

Question

I am detailing a few potential iPhone apps and wanted to know if it's possible to trigger an app (open the app) when the iPhone rings? Also, if your app is already open, can your app state be changed (change anything within the opened app) based on the iPhone ringing?

Any help on this would be appreciated.

Answer 1

You can use Core Telephony Framework to detect a call but for that your app needs to be in the foreground.

But launching an app when you get a call won't be possible with the iOS SDK.