Extra bottom space/padding on iPhone X?

In iOS 11, views have a safeAreaInsets property. If you get the bottom property of these insets you can get the height of the bottom padding while on iPhone X:

if #available(iOS 11.0, *) {
    let bottomPadding = view.safeAreaInsets.bottom
    // ...
}

(likewise for the top padding with status bar)

In Objective-C

if (@available(iOS 11.0, *)) {
   UIWindow *window = UIApplication.sharedApplication.keyWindow;
   CGFloat bottomPadding = window.safeAreaInsets.bottom;
}