App extensions allow you to extend iOS’s Share menu with any service you like, add browser actions to Safari or Chrome, use custom photo-editing tools in the Photos app, and integrate cloud storage services with any app.
Extensions are included along with apps, so just install an associated app to get its extension. You probably already have extensions for your favorite apps installed — they’re just disabled by default.
The 6 Types of Extensions
There are a number of different “extension points” in iOS 8. Technically speaking, Apple also considers widgets and custom keyboards to be extensions, although we covered them separately. Apple may add more extension points in the future.
Share: These extensions add new destinations to iOS 8’s Share menu. You can share content directly to a website or with a specific app.
Action: Actions allow you to “manipulate or view content originating in a host app.” This is the most vague type of extension, but think of the Safari or Chrome web browser. When you invoke an “Action,” it allows you to modify content on the page — for example, translating its content, inserting a password from your password manager, or something else.
Photo Editing: Photo-editing tools can function as Photo Editing extensions. These allow you to edit photos and videos directly within the Photos app.
Storage Provider / Document Provider: Storage provider extensions allow you to access and manage a source of files. For example, Dropbox, Google Drive, and Microsoft OneDrive could introduce document provider extensions. You could then open files from your cloud storage service in any app that support Apple’s standard file picker, or save files to any cloud storage provider of your choice.
Today: Widgets — officially referred to as “Today” extensions because they live in the Today view in the notification center — are a type of extension.
Custom Keyboard: Third-party keyboards are considered a type of extension, too.
Use Share Extensions
To access your Share extensions, tap the Share button in any app. (That’s that rectangle with an up arrow coming out of it.) For example, you can tap the Share button in Safari to share the current page to another app.
In the top menu — the one that begins with Message, Mail, Twitter, and Facebook — scroll to the right side and tap the More button.
You’ll see a list of installed Share extensions. Enable the ones you want to use, and disable the ones you don’t — yes, you can now even disable Twitter and Facebook if you don’t use them. You can also re-order this list by touching the handles and moving them up and down.
Tap Done when you’re finished. The Share menu will now show your favorite services and remember your preference. Just tap them to share the content from the current app with them — for example, tap Pocket to save the current page to your Pocket queue or tap Evernote to save the current page to an Evernote notebook.
Use Action Extensions
Actions also appear in the Share menu. For example, in Safari or Chrome, the first row of the Share menu contains sharing services while the second contains Actions. Scroll to the right side and tap More to customize them.
Enable any installed Actions from this list. You can rearrange the list, just like you can with Share extensions. Tap Done when you’re finished.
You can now tap an Action to use it. For example, tapping the LastPass button will allow you to fill in passwords in your password vault, directly in Safari or Chrome. You log into your vault if you’re logged out, save new usernames and passwords to LastPass, and more.
Use Photo Editing Extensions
First, head to the Photos app and open a photo or video you want to edit. Tap the Edit button in the top-right corner. After tapping Edit, tap the … button and then tap More.
Enable any installed photo editing extensions you want to use. In spite of the name, these can also be video-editing extensions. Apple’s own iMovie app provides a video-editing extension you can use to edit videos directly from the Photos app.
Photo editing extensions you enable will appear in the … menu. Tap an editing tool and you can use it to edit the current photo directly from the Photos app.
The Photos app will always keep the original version of your photo or video, so you can revert to the original if you don’t like the changes you made in the extension. Tap the red Revert option at the top-right corner of the photo-editing video to revert to the original.
Use Storage Provider Extensions
In any app that supports the standard iOS file picker, open the file picker and tap More.
You’ll see a list of storage provider extensions you have installed — for example, Dropbox currently provides one if you have the Dropbox app installed. Enable any you want to use.
The storage provider you enabled will now be available as a standard location where you can open files and save files. You can now access your favorite cloud storage service from any app that includes the standard iOS file picker, so Dropbox, Google Drive, OneDrive, and other services can now be first-class citiziens in iOS apps.
More apps will add extensions of their own in the future, so these features will only get more powerful. Hopefully Apple will continue to open up iOS in the future — user-selectable default web browsers and email clients, perhaps?
In any app that supports the standard iOS file picker, open the file picker and tap More.
You’ll see a list of storage provider extensions you have installed — for example, Dropbox currently provides one if you have the Dropbox app installed. Enable any you want to use.
The storage provider you enabled will now be available as a standard location where you can open files and save files. You can now access your favorite cloud storage service from any app that includes the standard iOS file picker, so Dropbox, Google Drive, OneDrive, and other services can now be first-class citiziens in iOS apps.
More apps will add extensions of their own in the future, so these features will only get more powerful. Hopefully Apple will continue to open up iOS in the future — user-selectable default web browsers and email clients, perhaps?