Niantic’s John Hanke cautioned recently that Pokemon Go trackers and their related websites may no longer be working in the near future, and it turns out he’s totally right on that warning.
When Pokemon Go updated recently they removed the “footsteps” mechanic that alerted players of how far away their next Pokemon was. The reason being that it would inaccurately display each Pokemon at its maximum distance, making it difficult or impossible for you to capture particular critters you were after.
Then Pokemon tracking websites like Pokevision popped up that would allow to accurately pinpoint the location of each Pokemon and were they would spawn; making them far easier to capture.
However, after the most recent update all of them just stopped working.
As for why they have completely ceased operations; it’s possible that Niantic has begun shutting down the services due to them facilitating cheating. Though it could also be happening because 3rd party services can in fact tax the servers too much, as something similar has happened to Ingress in the past.
While it’s a lot harder to hunt down those Pokemon, not all apps are down though. Poke Radar (which relies on user input to find Pokemon) is still functional.
Hopefully Niantic is working for a solution to the footsteps issue and didn’t just leave a whole bunch of players walking blind on the hunt for the elusive digital monsters.