The PiGlow is a small add-on board for the Raspberry Pi that provides 18 individually controllable LEDs.
The board uses the SN3218 8-bit 18-channel PWM chip to drive surface mount LEDs. Communication is done via I2C over the GPIO header with a bus address of 0x54. Each LED can be set to a PWM value of between 0 and 255.
To get the module set up and ready to go you can use the one-line product installer:
curl -sS https://get.pimoroni.com/piglow | bash
And follow the instructions!