Sometimes a full size Arduino is a bit on an overkill if for example you just want to blink one LED.
Fortunately there is a smaller and cheaper version of microcontroller used by Arduino called the ATtiny. We have included one in the workshop kit, it's a small 8 pin chip that is stuck into a foam pad.
You can program this chip using your Arduino. Instructions are provided here and you need to follow the sections relevant to using Arduino (as ISP) to an ATtiny.