A plugin to control relays or other things on the GPIO pins of your raspberry pi. For example turn the power of printer, the light or a fan ON and OFF via the web interface.
A plugin that adds buttons to the navigation bar to toggle GPIO pins on the Raspberry Pi. I use it with a 4 relay board, and printed this case for it: https://www.thingiverse.com/thing:2975944
Just hooked up the GPIO pins with the relay board, and now I can turn the power of the printer, the fan and the light on and foo with OctoPrint.