Mysterious, moving icon with "8" on it on top right of an iPhone 7 Plus
My girlfriend has an iPhone 7 Plus, and the recent months a mysterious moving icon with what seems to be an 8 on it shows up on the top right corner of the home screen and moves steadily towards the corner and out of view. It looks to exist between the top layer app icons + battery + time info and the background wallpaper. She has tried changing the wallpaper and it still appears.
What's happening? To my knowledge, apps on iOS can't access the home screen in this way.
She bought the phone from well known store in Norway, brand new.
Here are two screenshots that we've been able take, because it moves fast!