Just a word of warning for those Apple users out there - the new supplementary iOS update 13.1.2 is causing issues with iPhones getting stuck on the Apple logo with a spinning circle, while trying to upgrade. The phone then becomes unresponsive and seemingly bricked. The usual soft reset procedure does not work. Happened on my iPhone 11 Pro, but users are reporting it happening on X, XR, XS, 11 and 11 Pros.
On newer devices you have to quickly press VOL UP, followed by VOL DOWN, then press and hold POWER until it turns off. It may then turn back on as normal, or like me, you may have to repeat the above procedure. Then go check for updates again and you will see you're still on iOS 13.1.1. For me, a second attempt installed OK.
I would advise waiting until iOS 13.1.3 to be released before updating, just to be safe.