What are apropriate uses for NumberSync?

Hello @Anonymous

The details about number sync for the iPhone 4 or any other device hasn’t been released to us yet, as it was just announced.

Essentially, NumberSync will allow you to share your phone number, using a combination of network and device  software, to any other compatible connected device you own. This will work when your smartphone isn’t with you, nearby or even powered on. 

We expect to launch NumberSync on our first device fairly soon with additional devices launching in the holiday timeframe.

Check out our Consumer Blog for current info and future updates.

Thank you,

Gerald

Thanks, got it working.

@Anonymous Technically, if you had four iPhones they'd each have their own SIM and own number...

Hypothetically, though, using the "upgrade devices to Wi-Fi Calling" feature if:

• each device was logged into your iCloud account
• one had an AT&T SIM and the others didnt
• you upgraded each one to a Wi-Fi Calling device

they would all be able to use your AT&T number over WiFi.  It's a very odd example but it would work.  The real world example is perhaps for a user like me.  My 6S Plus is registered to AT&T with a number.  My iPad Air 2 and MacBook Pro can both be upgraded to use Wi-Fi Calling (a.k.a. AT&T NumberSync) and make calls on their own without my iPhone even having to be on or around.

I'm still trying to figure out the value in this other than making calls while I left my phone at the office, but it's a cool feature nonetheless.

Let me know if that helps or you have other questions.