In some cases, the issue is with the application you used when the blue screen showed up. Sometimes, the app update can fix the problem, which is why you should try it out. Go to the App Store, select the Update, and choose the app you want.
If an update isn’t helpful, maybe the app is faulty. If you noticed that the problem occurred shortly after you started using a certain app, and the update did not fix it, delete that app. To do this, choose the app from the home screen. Press and hold your finger on it, and you will see the cross on every app. Simply click on that cross and the app will be deleted.
Users have reported that blue screen issue usually starts when they use Pages, Numbers or Keynote. When pressing the home button, the blue screen is there, after which the phone reboots. Choose Settings, tap on iCloud and go to Documents and Data. Set Numbers, Pages, and Keynote to off.
Go to Settings, General, and choose Software update. Click on Download and Install.
Back up your data. Go to Settings > General > Reset > Erase all content and settings.