Extensibility is one of the biggest features of the iOS 8 update that was released publicly earlier today. In this post we talk about Custom Action Extensions, that can modify the content of other apps to do things like translate text or autofill forms.

Here’s how to add and use Action Extensions in iOS 8:

• Install an iOS 8 compatible app that comes with an Action Extension. 1Password is a great, free password manager app that has an Action Extensions to autofill your saved password in webpages.
• Once you’ve installed the app, open an app where you’ll use this extension. We use Safari to autofill login credentials on a website.
• After opening the webpage, tap on the Share icon to bring up the standard iOS 8 share sheet. The first row of icons contain Share extensions and the second row contains Action Extensions.

• Scroll the second right to the right to reveal the More icon with three dots.

• You’ll get a list of all the available Action extensions. New ones are disabled by default, and you’ll have to switch it on. So let’s switch on the 1Password extension.

• After doing that, tap on Done, and you’ll now see the new action extension available in the row of icons.

• Now tap on the new Action Extension, in this case 1Password, and you should see the Action Extension bring up its own UI or do whatever task it is supposed to do.
• In case of 1Password, it brings up a password field to enter the master password, after which you can access the saved login info to autofill in the current webpage.

iOS 8 app updates are starting to roll in, and if you don’t have Action Extensions available right now, you’ll likely get one when you update apps on your device.

What’s your favorite iOS 8 Action Extension? Let us know in the comments below.