Many moons ago as I transitioned from ereading on my monochrome palm m500 to a color Tungsten T, I immediately noticed that my eyes had more strain, particularly late at night. This set off a mission to find ereaderware that would let me try to replicate the m500's odd greenish backlight, but over the years as I experimented more I realized red was even better than green or yellow/amber for avoiding eye strain. Eventually I preferred system level lighting changes, like cf.lumen (root) and kcal color control (kernel hack), though currently I use a simpler app called twilight on my unrooted pixel 3a, this way I can get a consistent experience no matter what readerware I use, as well as filtering while I read email or something in a browser. And of course the individually backlit amoled works better with any solution than LCD where the white backlight always leaks through. Official night filters from microsoft, google, apple and amazon are better than nothing, but from what I've seen they're also pretty weak sauce, like 10 years behind. Congrats on catching up with f.lux folks, but I want more than a warmer color temp. When I first started thinking about adopting some apple products, I worried about whether I'd find solutions like cf.lumen there. Honestly, I figured something like twilight would be the best I could do, if indeed it was allowed at all (there are legit security reasons for not wanting an app to be able to mess with what's being displayed everywhere). I was shocked to discover an accessibility feature built into iOS that would let me do exactly what I wanted, and on top of that, a built in way of making it a shortcut for quick easy access. Add to that iphones adopting amoled screens and that takes away a big mental barrier for me moving to ios. links: https://yourstack.com/pro-tips/465-red-light-mode From a platform that once upon a time insisted that their own experts must control every aspect of the user experience and users ought not be trusted to make too many of their own choices, this is surprisingly versatile, even considering how much more flexible Apple has been ever since Cook took over. The way it works is a little different from those links now with home buttons disappearing, but I gather there's a side button to trigger the triple click shortcut. Until yesterday I wondered if I would ever go through with moving away from android, but now it seems a lot more likely. Since I just got my pixel I'm probably several years away from any move, but I'd need that time to save up to pay the apple premium and to get over my penchant for smartphone bargains anyway.