I got a screen protector in Apple Store - the person who helped me select the phone installed it for me.Hate screenprotectors. When I see friends or coworkers with screenprotectors on their smartphones, 8 out 10 I always see the rainbow effect on the sides of the screen.
Also the ones with cutouts are simply fugly af
Every time I show it to someone they ask me why I am not using a screen protector?
Mine was something from Belkin (plastic not tempered glass) sold in the Apple Store and the Genius made such a good job installing it that it's not even visible there's anything on it. They used some sort of machine to apply it - very cool.
There's zero rainbow effect on mine and no distortions, absolutely nothing.
I wish I could take a photo but I only have one iPhone...