The Inkcase, as Gajah has named it, is a smartphone case that is also a Bluetooth accessory. It has its own screen, battery, storage, and (based on the video) I think it even has its own CPU. All that extra hardware adds considerable weight and nearly doubles the thickness of the smartphone but it also opens up some interesting possibilities.
Gajah is planning not one but 3 cases. This week they showed off cases for the iPhone 5, and the Samsung Galaxy Note 2, but their signage also hits that they have a case for the Samsung Galaxy S4 in the works.
The iPhone case has a 3.5" E-ink screen with a screen resolution of 360x600, while the Note 2 case has a 500mAh battery, 512MB of RAM (that could actually be Flash storage), and a 4.3" digital ink screen with a screen resolution of 600x800. Yep, it's that knockoff E-ink screen that has been showing up on a number of ereaders.
Gajah has developed several apps that work with the Inkcase, but this is just the beginning. The units on display could only be used to display photos from an album or read an ebook, but Gajah is planning to enable the Inkcase to show you latest Facebook or Twitter updates, or current weather data from Google Now.
But who cares about that when you can do this:
Speaking of which there is a reading app which works with the Inkcase. It's called EpiReader, and it builds on Gajah's long history of developing ereaders. You can see it in operation in the video that Engadget posted. That video is in Chinese but it is better than nothing.