It's a very minimal input module. Many GPIO pins are exposed so that headers can be soldered onto them. Additionally there are pads for a WS2812/Neopixel compatible RGB LED.
When booting up this LED is lit in green color. Its color and brightness can be controlled via the commands:
> ./ledmatrix_control.py --brightness 255
> ./ledmatrix_control.py --get-brightness
Current brightness: 255
> ./ledmatrix_control.py --set-color yellow
> ./ledmatrix_control.py --get-color
Current color: RGB:(255, 255, 0)