Originally got this for a pwnagotchi. Turns out to be easily programmable. With a raspberry pi 0w, it is low profile enough to be a hacker's smartwatch. Drawing speed is on par with other epaper displays at roughly 1frame/sec, with some ghosting to be expected, but a full screen refresh can clear all ghosting effects. Occasionally there would be a grey background instead of white, although that was when the device was powering down so I suspect this would have to do with residual charge rather than the screen itself. Despite it not as bug-free as the displays found on other ebook readers, it has a high reliability rate for drawing when used as a smartwatch display, and its interface is easy to program. So far I've used C and Python. A must-have for anyone with an RPi.