My wife has had an iPhone for quite some time, currently has an iPhone6s+
I had an older non-retina iPad... and recently bought a new 2017 model on Black Friday.
I took the old iPad, reset to factory settings, and gave it to my wife.
She asked me to install an app I had written to it for her, so I had her iPad on my desk this morning.
Her iPhone rang (incoming call)...... but SO DID THE IPAD!
the screen on the iPad said Incoming Call [xxx-xxxx] slide to answer
WTF? this is NOT an LTE iPad (Wifi only)
So why did it accept a phone call (or how for that matter)
I don't answer her phone, so I didn't attempt to see what would have happened,