Continuity Markup in iOS 13, iPadOS and macOS Catalina 10.15 or later lets you annotate documents on your Mac using your iPhone, iPad, or iPod touch. It works like magic. In this short step-by-step tutorial, you're going to learn how to use this feature to mark up Mac documents such as PDFs and images on your nearby iOS device with your Apple Pencil or finger, zero setup needed.