PikaPika was an app (available on Android and iOS) which provided a very precise radar to the Pokémon Go players all over the world. It had around 700 000 downloads.
Few days after the launch, the team reverse engineer the game to understand how it work with the help of other developers all around the world.
We did a back-end API using NodeJS and MongoDB technologies to fetch and save Pokemon positions from Pokemon Go servers on our database,
We let our source code public.Check the Github