seems pretty neat. I think they are on back order though.
It's a microcontroller development board. It can do about anything you can think of electronically. It takes inputs, whether it's a sensor, switch, analogue voltage, etc, and creates outputs. Those too can be many types of outputs, relays, led's, wireless modules, solenoids...anything with the right voltage and speed. The neat part is that you can write code to change its behavior very easily. This one is super cheap having a development board hooked to it. Usually a lower end chip costs this by itself.