With iOS 12, Apple launched a new Screen Time functionality for monitoring device and app usage. As part of that, TechCrunch reports today that Apple is cracking down on third-party screen time trackers in the App Store with stricter reviews and in several cases, removal from the App Store.

What’s important to note is that these applications had not been using any official, Apple-approved frameworks or methods for tracking screen time. Instead, they relied on combinations of VPNs, MDM solutions, and background location functionality. In some cases, they create privacy concerns for Apple and the end-user.

TechCrunch outlines several applications affected by Apple’s crackdown on screen time workaround apps. One such app is Mute, which publicly announced its removal from the App Store in October, while another is the three-year old screen time app Space, which was removed in November.

Several other applications were also reportedly removed from the App Store or had updates rejected, but did not want to be publicly named. In most cases, developers were told they were in violation of an Apple Store guideline related to location functionality:

Other apps were cited for violation of a different guideline related to how they implemented public APIs.

However, it hasn’t been all bad news for some of these screen time applications. Both Space and Mute, after going public about their removal from the App Store, were contacted directly by Apple for additional details on user privacy and how they use location-based services. In the case of both, the apps were reinstated to the App Store.

Not all applications have had such luck, though, including OurPact and ACTIVATE FITNESS. Both of these applications were informed by Apple that they could no longer use MDM – mobile device management – technology for building screen time functionality.

Amir Moussavian, CEO of OurPact parent company Eturi, said the following in a statement to TechCrunch:

Other applications, such as Kidslox, haven’t been completely removed from the App Store yet, but instead Apple is rejecting recent updates to the apps. Kidslox CEO Viktor Yevpak accused Apple of “systematic destruction” of the third-party screen time management industry in a blog post.

Apple did not comment on what seems to be a crackdown on third-party screen time applications, but TechCrunch cites a source familiar with the matter in explaining that Apple is not necessarily targeting screen time apps. Instead, it’s part of the company’s ongoing process to clean up the App Store:

Apple has a history of going against applications that mimic built-in iOS functionality, but whether or not that is actually what’s going on here is unclear. The timing of the crackdown on APIs used by third-party screen time apps, which is just months after the introduction of the first-party Screen Time feature, is certainly suspicious.