In case anyone is interested, the method used is polarization, and the film is either called a polarisation filter or a polarising filter depending on how it tr

In case anyone is interested, the method used is polarization, and the film is either called a polarisation filter or a polarising filter depending on how it translates in Amurica. I don't know any decent-looking vendours who sell them, be it for iPhones and other devices, so it might be your chance to get entrepreneurial