How does Truecaller intercept incoming phonecalls on the iphone to display caller ID?
I didn't think this was possible from within the app?
Specifically, if I wanted to build this functionality, what protocols would I go about using?
On an iPhone, without jailbreaking it:
- you cannot intercept a call in any way
- you cannot determine the phone number nor the caller ID identifying information regarding the call. Even if you could there
is no way to alter what is displayed on the call screen
- you cannot block the call
- your program can get a notification when a call is being made/terminated etc. But only if your app is executing in the
foreground at the time of the call or if the app is in the
background and has a relevant background mode (even then you can
only know there is a call in some circumstance, depending upon what
you're doing in the background and what state your in etc. Its too complex to describe the exact situation here briefly)