When the iPhone X was first launched, and in iOS 11, when closing apps in the App Switcher you could only hold on an app, then swipe up (or tap the close button). iOS 12 removes this annoyance and lets you swipe up to close apps now, without holding.
Swipe to try again when Face ID fails
Now, if Face ID fails to detect your face, you can swipe up to continue trying again, instead of turning off your iPhone and going back into this. This also brings up the passcode screen.
Face ID improvements
Beta testers of iOS 12 claim that this update improves Face ID's reliability and speed, and allows you to get in your phone quicker than ever before. We'll have to look and see if this is correct.
You can now create your own animated emoji on the iPhone X, Xs and XR. Customise your hairstyle, colours, facial features and more, and use it to record videos with it! You can also save it and make as many Memoji as you want.
Apple nows allows you to record up to 30 seconds of Animoji video - previously it was 10 seconds. Along with this, there are four additional Animoji characters added in iOS 12.