Auto picture rotation

few years ago, i had a software to automatically rotate pictures. taking a picture in portrait, it shows it as landscape, but the picture should be portrait to be able to see it correctly i.e legs on the bottom and face on top, instead of looking a picture landscape and seeing the legs on the left and head on the right.
this was something really helpful for viewing all of my pictures without taking the effort and rotate them (some thousands) one by one

that would be something nice to add in Mylio.

Almost all cameras do this automatically nowadays when you change their orientation. Are you talking about pictures taken with an old camera that didn’t support auto-rotation?