In the post on the Blizzard forums, community manager Tom Powers announced that they have taken a look at some third-party apps for Overwatch and have clarified that some of these apps breach the end user licensing agreement, and that further use of such apps could potentially lead to a perma-ban, something that Blizzard is taking a no-nonsense stand on.
While Blizzard does not come outright and say it, the apps that Blizzard seems to be referring to are Visor and Pursuit. These are apps designed to provide users with real-time in-game stats meant to help them improve their gameplay, although Blizzard seems to think that they compromise the “professional integrity” of the game.
Blizzard notes that they will not be banning players who have used the app, but have notified them by email to ask them to stop or risk facing a ban. “In this case, we’ll be reaching out to users that we’ve detected to be using this unauthorized software; to notify those users that those specific third-party applications are not permitted and do not align with the Blizzard EULA. Furthermore, we will be requesting those users to immediately remove the unauthorized software to avoid account suspension.”