One of the features in iOS 9 I’m most excited about is cellular continuity. Apple is building on the continuity features introduced last year that let an iPhone be linked with a Mac and/or iPad so that phone calls could be made or received from any/all of those devices.

It was a great feature, and more than once in the past year I’ve used continuity to pick up a phone call on my iPad or place a call from my MacBook. But the major problem with continuity was that the devices all had to be living on the same WiFi network for it to function. So if I sit down at my desk and my iPhone is still on its LTE connection rather than home WiFi, there’s no continuity.

That’s changing in iOS 9, and I’ve been trying it with iOS 9 Public Beta. T-Mobile is the first (and so far only) carrier to support what Apple’s calling “cellular continuity,” which fully develops this feature so that your devices no longer need to live on the same network to see each other.

What this means is that if you iPhone dies or you just want to go someplace with only your iPad, your iPad will be able to make and receive calls using your mobile number. In other words, you don’t need your iPhone with you and it can even be turned off, but you can still make/receive cell phone calls with an iPad on LTE or WiFi wherever you are.