Last year, Apple removed hundreds of thousands of VPN apps from the Chinese iOS App Store due to government intervention. Now, it looks like the Chinese government has gone behind apps that make use of CallKit API. This is because Apple is sending developers an email informing them that they need to remove the CallKit framework from their app in China due to government regulation.
Once developers remove the CallKit functionality, their apps would again be listed on the Chinese App Store. Apple is making this move due to the new regulation enforced by the Chinese Ministry of Industry and Information Technology (MIIT).
Apple had first introduced CallKit with iOS 10 and offers VoIP apps a way to make use of the native in-call Phone app and UI. The framework is primarily used by VoIP apps and the move from the Chinese government seems to be a move to take them down. WeChat, which is massively popular in China, had CallKit framework integration for a short period of time before it was again removed from the app. No wonder then that Skype, a popular VoIP application from Microsoft, was removed from the Chinese App Store.
As a side effect of this move from Apple, apps that use the CallKit framework to pause audio when an incoming call arrives have also been removed from the App Store.
Apple has had to remove a lot of apps from the Chinese App Store over the last year to meet the stringent regulations of the Chinese government. The company has already removed hundreds of thousands of apps from the Chinese App Store to comply with the government regulations. To comply with the Chinese government regulations, Apple has had to take a lot of steps which it otherwise would not have. Apart from removing VPN apps from the iOS App Store, this also includes shutting down the iTunes and iBooks Store in China within six months of its launch.