OAXIS' InkCase 5 is an E Ink case for Apple's iPhone 5 phone that has a 3.5" E Ink display that can act as a secondary display. The case comes with an application that allows you to control and manage the E Ink display to show images, notifications, reminders and other. The case uses Bluetooth to connect to the iPhone.

The InkCase 5 is now shipping for $169.99 in the US.

E Ink display info: 
3.5" E Ink panel