The device is awesome, hats off to you for creating this. I have a micromanager boss who comes into my office a lot and sometimes I have nothing to do, because I have finished my work and I want to relax. This saves my ass, the only drawback I will put on this is if you added documentation inside the packaging it would go more smoother.
As a product it's a fun little thing. As a FOSS reference project, it is outstanding.
As a hobbyist in electronics I found the schematics and plans to be really educational and well presented, in a GitHub repository. I bought the physical asset to reward the seller for their contribution.
Overall, very happy. 4 stars product and shipping because there was an issue with the shipping, which the seller corrected quickly, and because as a Linux user the product is a bit tricky to use effectively without hacking about in my settings (the linux way) and trying to find a way to make it do something useful.