As part of a feature set called Continuity, Apple launched Handoff in iOS 8. Handoff allows users to start an activity on one device and then continue it on another. In iOS 9, Apple introduced the ability to index these user activities in Spotlight.
There are several advantages to this because apps that support Handoff hardly need to do anything to support Spotlight indexing and vice versa. So, even though this chapter is all about search and Spotlight, you will also learn something about enabling Handoff for your app.
The philosophy behind user activities is that whenever your user interacts with your app, you create an instance of NSUserActivity. For Spotlight, these activities revolve solely around ...
