Pokémon Go players using third-party trackers to find the game’s rarest monsters may want to take notice. Niantic has demanded that the creators of PokeSensor and PokeSearch discontinue work on their apps immediately. The request was upheld by both teams. According to separate blog posts, the trackers are formally shutting dawn.

The news went live Monday evening, and it’s sending shockwaves around the Pokémon Go development community today. Perhaps the most in-depth explanation of the events came from PokeSensor’s Patrick Ballard. To make a long story short, Ballard reportedly received an email from Apple this weekend suggesting that The Pokémon Company had taken issue with Sensor’s use of the Pokémon Trainer Club API.  As a result, it was mandated that the project be removed from the App Store immediately. Fearing future repercussion and less need for an Android build, development has ended.

Read: Pokémon Go Screen Block Message Plagues Users Of Chinese Phones

Despite the forced shutdown, however, Ballard admits that he has “no ill will toward The Pokémon Company or Niantic” for the decision. The app was able to exist unfettered for nearly a year, and for that he is grateful.

While equally appreciative of what’s been a “good” ride, the creator of PokeSearch was slightly less kind. The developer didn’t provide any explicit details about the closure beyond receiving a Cease and Desist request. “Hopefully one day Niantic will realize the reason people flock to external maps isn't because they're all cheaters,” the final blog post concludes.

PokeSearch will likely have stopped working by the time you read this article, while PokeSensor will remain active for current users until API changes eventually render it useless.

Third-party trackers for Pokémon Go remain popular due to player dissatisfaction with Niantic’s official implementation of the feature. The current Nearby menu works fine, but many enthusiasts feel it’s not nearly as helpful as the defunct “three-step” system. Trackers have long been perceived as a semi-legit alternative to fix that problem.

This news is one of many recent developments involving Niantic’s ongoing commitment to stopping unsanctioned play of its app. While some trainers may not consider third-party trackers a form of cheating, the game’s development team feels they tarnish the experience just as overtly as GPS hacks. Not only have we witnessed frequent ban waves over the past few weeks, but tweaks have also been made to gameplay mechanics to discourage the use of outside tools. As Pokémon Go nears its one-year anniversary, any means of gaining an unapproved advantage is being taken offline.

Pokémon Go is available now on Android and iOS.

Do you think it’s right for Niantic to shut down Pokémon Go trackers? Should they be viewed in the same vein as cheats or hacks? Tell us in the comments section!