Important iOS changes to know about
If you valued the extended keyboard in landscape mode, note that it is absent
in iOS 11. Key order in the bottom row also changes when rotating an iPhone (but not an iPad), swapping the Emoji and 123 keys, and moving the mic key even further. Google’s Gboard lets you make your own custom keyboard.
If an app no longer appears in search results after upgrading, locate it in the list In Settings > Siri & Search. Tap its name there and turn on the Show App switch; this isn’t available for every app, but where it is shown, it initially matches the Search & Siri Suggestions item’s state, hiding the app in results as well as its contents.
Connectivity clashes
As is common with updates, iOS 11 can result in Bluetooth and Wi-Fi oddities, and these can affect pairing with a Watch. After upgrading to iOS 11 and watchOS 4, your Watch may lose its connection with your iPhone.
Try shutting down both devices and then powering them on again. If that doesn’t help, you’ll need to unpair them, which is best started on your Watch. Once they’re unpaired, turn your Watch off and then on again, before pairing it with your iPhone in the normal fashion. Similarly, unpairing and then pairing can fix other Bluetooth issues.
The Wi-Fi and Bluetooth buttons in Control Centre no longer work as you might expect; turning them off in iOS 11, merely disconnects from networks and devices until 5am. This is to ensure AirDrop, AirPlay, Continuity, and Watch connections are unaffected. This means that power is still supplied to the radio hardware. If saving power is your aim, you’ll need to turn them off in Settings.