Here it is, iOS8 and a lot of changes it brings to iPhone and iPad users. Some of them are minor and most people will probably not even notice them, but one thing will significantly change the whole user experience: it’s called App Extensions. From a developer’s point of view, it’s an incredible way to enable users to use our apps in ways we could previously only imagine. So what is it really? App Extensions is a group of 6 functionalities that can be added to an app to extend its functionality. 

Today
This is extension allows us to show a small, dynamic view in the “Today” section of the Notification Center. Until now only apps like Stocks or Weather had the ability to display information on this view. Now every app can do that.

Share
It’s really easy to guess what functionality this extension provides. It allows user to share content from one app by using another one. This feature was first introduced by Apple and enabled users to “tweet” images. Later, Facebook support was added, and now users can use any app (which has the Share extension) to share content. It’s a big opportunity, especially for social network apps.

Action
This extension is reserved for apps that will be rather invisible, but very useful: they are able to modify content within other apps! A great example presented by Apple was an app that is able to translate the content of a website within a Safari browser, without having to leave the app, or even reload the page!

Photo Editing
You probably have heard about apps like Instagram and Simple Sketchbook. What if you could use their features on any photo from the Photos app, but without opening them? This is exactly how this extension works.

Document Provider
Thanks to this extension, users will be able to keep all his data from many apps in one place – and it no longer has to be iCloud! Document Provider enables both upload and download of data from an external service, like Dropbox.

Custom Keyboard
This is probably one of the most surprising extensions provided by Apple. Now users will be able to use a custom keyboard, and developers are enabled to create their own sophisticated keyboards.

Oh, and one more thing… app extensions cannot be submitted to the App Store as standalone apps. For now, they can only be a part of a bundle in standard applications.