2017-10-19

Updated the custom keyboard documentation to include changes added in iOS 11.

2016-11-14

Added information about APIs you can use to implement a Photo Editing app extension.

2016-03-21

Added two new chapters: Audio Unit and Content Blocker.

Updated Table 1-1 to list app extension points available in iOS 10 and macOS 10.12.

2015-03-09

Updated the descriptions of the FinderSync and Document Provider extensions.

Corrected information in the Document Provider chapter.

Noted, in Sharing Data with Your Containing App, that starting in iOS 8.2 you can safely use the UIDocument class to coordinate shared file access.

2014-12-10

Expanded the discussion in the "Specifying When a Widget Should Appear” section.

2014-10-20

Expanded the discussion in the "Specifying When a Widget Should Appear” section.

Improved the list of capabilities enabled by the RequestsOpenAccess Info.plist key, in Configuring the Info.plist file for a Custom Keyboard.

Added a new section: Ensure Your iOS App Extension Works on All Devices.

2014-10-16

In the API Quick Start for Custom Keyboards section, added a code snippet for deleting forward and added a link to CFStringTokenizer Reference.

Expanded the discussion in Specifying When a Widget Should Appear.

2014-09-17

New document that describes how to develop an app extension, which is a bundle that provides functionality to other apps in a specific context.