Creating Photo Editing Extensions
Provide custom functionality in the Photos app by bundling an app extension.
Overview
You can incorporate your app’s features directly into the Photos app in iOS or macOS by building an app extension. With a photo-editing app extension, people can edit media, apply your app’s filter effects, and build slideshows, books, or custom content, such as collages, right in their Photos app.
Implement and bundle the app extension
Adopt the PHContentEditingController protocol to create an app extension that adds to the photo editing options and capabilities in the Photos app. Creating such an extension also requires using the following classes from the Photos framework:
PHContentEditingInput to reference the photo or video you want to edit
PHContentEditingOutput to save the results of an edit
PHAdjustmentData to describe an edit operation
Include the app extension in your app bundle, and the system installs it in Photos at the same time someone installs your app.