The Ruiz brothers over at Adafruit have found a way to create a Pokemon tracking device by hacking into the Pokemon API. Warning: make a separate account because this is definitely against their terms of service! They use a Raspberry Pi Zero and a special 3D-printed case which has three LEDs to indicate what type of Pokemon is nearby – common, rare or legendary. All the code is on Github and you can find instructions and the files for 3D printing over on the Adafruit tutorials hub.