Sometimes, you change your app's UI to offer more options as a result of a user's action. And in such cases, it might be a good idea to move VoiceOver's focus to these new options. We can do that by sending a layout changed notification.

Two examples from Apple where they seem to post a layout changed notification to UIAccessibility to move VoiceOver's focus to new options. First one is the reminders app. When double tapping the Date & Time button, there is a new bar that appears on top of it with some predefined date options, and the focus moves to the first option in the bar that appeared. The second is the camera app. At the top of the screen there is a camera controls button that is collapsed by default. If you expand it, some new options appear further down the screen, right after the zoom options, and VoiceOver focus will move to the first one of the new camera controls presented.