3D printer has been used to makes its components to give appearance of "module Lure" (the component we use in the game for to attract pokémon at the Pokestop), it has been developed using Python code, all to allow the lamp illuminates three LEDs depending on the type of pokémon detected.
When a normal Pokémon appears near our position, the small light turns on, leaving the middle and high for more pokémon category.
The device connects to the unofficial game API, so it can be disabled at any time and change the detector into a useless piece of plastic, but in the meantime able to go through the streets "like a boss".
On the same website you have both the list of components used in the project as the circuit diagram and software that has been used.
While Niantic is preparing bracelets may be used to hunt pokémon in the streets, but today here we got an alternative solution to at least detect them.
In the video you can see below you have the presentation of the project, described in detail in adafruit.com for those who dare to do the idea.