Blocking access to various applications in China is nothing new. Direct access to applications such as Facebook, Twitter or Instagram, so basically to applications that cannot be controlled by the Chinese government, is impossible without the use of a VPN. The group of previously mentioned applications is joined by Signal, which is considered to be one of the safest messengers in the world.
Signal was constantly gaining more and more customers in China, which was certainly a threat to the Chinese government. The app in the App Store received a rating of 4.9. However, from 16th of March, direct access to it is blocked - the application can be downloaded to the phone, but the mere use of it without a VPN turns out to be impossible. This information is also confirmed by the Greatfire.org portal, where you can constantly monitor which websites and applications are blocked in China.