Not sure why you'd want/need a 'privacy screen' for your iPad - if you have someone/people invading your space to that degree when flying, you have a different problem. That being said, maybe you are thinking of an anti-glare protector... I use them on all of my (regular, 9.7") iPads ... <
https://www.amazon.com/Supershieldz...+antiglare&qid=1547581542&sr=8-11&ref=sr_1_11> FWIW. Also, I'm a big fan of glass (screen/display) protectors... so combined you have the best of both worlds. (Remember the glass one goes on first, then the anti-glare outermost...). To the 'darken' question... it gets rid of glare, it does not darken the image.