App crash after a long time loading iOS12? Normally, I can launch these apps. But after a point of time, all of the apps will crash after a long time loading. 

I have tried to restart my phone, and clear all recent apps. But still not working.

My environment iPhone 7, iOS 12 with all apps update to latest version which compatible with iOS 12.

I have recorded a video here.
I had the same problem a few days ago. What fixed it was uninstalling the app and reinstalling it. 

Make sure that you save all your data first.

From this article:


  Press and hold the Top (or Side) button until the slider appears.
  
  Drag the slider to turn your device completely off.
  
  After your device turns off, press and hold the Top (or Side) button
  again until you see the Apple logo.