Already available to AT&T, Sprint, and T-Mobile users, the feature lets devices signed into your iCloud account make or receive calls.
Allow Calls on Other Devices
Allow other devices signed into your iCloud account to make and receive calls using your carrier account even when your iPhone is not nearby.
You can selectively enable the feature per device via the Settings menu on your iPhone.
Other enhancements in iOS 10.3 beta include a hidden one-handed floating keyboard for iPad, a switch to APFS for the iPhone's file system, Find My AirPods, WebKit improvements, and more.
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