A few weeks after Google Pixel smartphones received Android's Instant Tethering, the same feature is now rolling out to Nexus devices. The Pixel, Pixel XL, Nexus 6, Nexus 5X and Nexus 6P running Android 7.1.1 and above can share their data connections, while all those devices, including the Nexus 9, can only use shared data connections.
This feature will be very convenient for anyone with multiple Android gadgets, as it will allow them to use share a cellular data connection via Wi-Fi. The only requirement is that they need to use the same Google Account. Once you setup your devices, every non-host devices will use the shared data connection whenever in range and will automatically disconnect after 10 minutes of sitting idle.