Posted: 13/07/2015 at 13:21
Photos rotate because software puts that information into the the 'EXIF' data on the photos. Google 'remove exif data' and once you have an app which does that, you can rotate them in a photo editor and they will stay put. There are other reasons for removing EXIF data - privacy being the main one as it can contain location information and more..
It's mainly an issue for Apple devices, so the lack of privacy should be no surprise!