All Pokémon GO maps have been taken offline, including unofficial scanners, trackers, Gym Huntr and all other map solutions that rely on accessing Niantic’s servers for data. All Pokémon GO clients (the official game client, maps, various apps) rely on accessing Niantic’s servers via a built in server side API layer. The API layer dictates the minimum app version that can access the data and maps use/emulate a set version API client. A new version of the API was recently forced to update to 0.95.3. To learn more about why all the maps are down, click here.
Source: Pokémon GO Hub