Developing for Apple Watch, 2nd Edition

Adopting Handoff in the Extension Delegate

Handoff is a technology permeating many Apple platforms: iOS, OS X, and watchOS. It relies on the concept of a user activity, which describes the thing that the user is doing. This could be editing a document, ordering a pizza, or playing a game. On iOS and OS X, adopting Handoff and user activities allows you to transfer that activity from one device to another. You can seamlessly edit a document on one device and then open the same app on another device right to the same document. On watchOS, Handoff has two main purposes: to continue an action on the user’s iPhone, just as you can among other Apple devices, and to navigate into the watch app from other user interfaces, such as the app’s Glance. ...