I lived in China for 9 years through most of the banning. I remember the day Twitter stopped working because the US embassy in Beijing was posting embarrassing AQI readings on their Twitter account (“crazy bad” for a reading that was so high they didn’t expect the label to ever be used). I was there when Facebook became blocked and when google became blocked. YouTube, however, was already blocked in 2007 when I started working there.

None of those services need apps, I never used apps to access them.