Ruby, Screen time on your Mac, iPhone and iPad exist! just set it up and you don't need to set your phone on airplane mode. I have down time on my devices so that I can only use my phone, tablet, and laptop until 10 in the evening. Some apps are restricted, like Safari, Instagram or Pinterest. I also shut down my laptop at 10 (okay, I only put the lid down) and try to wind down by listening to a podcast, audio book while knitting or drawing something. No need for air plane mode or a cover for screens. When I go to bed, I leave my iPad downstairs so that I don't watch Youtube in bed. My sleep isn't better because of this but I hope that it at least has a small positive effect.