I have no idea how it happened but my wife has accomplished it without knowing how or what it is. I'd like to turn it off but I dont even know what its called.
The Iphone seems to have been paired with our IPad. When someone calls the iPhone, the iPad rings (as well as the phone) and we are able to answer the call using the iPad (or the phone).
Bluetooth is off on both devices and the ipad has no sim card - both are connected to home wifi.
What program/technology is causing this pairing? What's its name so I can google it and turn the annoying thing off ?