The SRAM chip shares the SPI port the eInk display uses, so you only need one extra pin to make the display work.
There is even a MicroSD socket so you can store images, text files or anything you wish to display.
For ultra-low power usages, the onboard 3.3V regulator has the Enable pin brought out so you can shut down the power to the SRAM, MicroSD and display.
Product Dimensions: 43.6 mm x 43.0 mm x 5.0 mm / 1.7" x 1.7" x 0.2"
Product Weight: 9 g / 0.3oz
Below you can see an example of how the display works
To find the library click here
For more information check out the video here