Apple - Is it possible to have a Dvorak keyboard on the iPhone?

App Store -> type "Dvorak" -> Dvorak for All -> Have fun!

There are also a couple of paid apps.

The built in keyboard settings only allow you to use different international layouts. You'd need to use a third party keyboard application.

In my case I wanted to use Dvorak layout with external bluetooth keyboard on my iPad but unfortunately it didn’t work with third party apps. Happily it can be set with standard iOS settings – go to Settings, General, Keyboard, External keyboard, English and select Dvorak.