Apps to reduce blue light at night

There is more data coming out all the time about blue light inhibiting melatonin and affecting sleep. I can use f.lux on my Mac but just want to check--the closest topic to this I found in the forums has had very few posts over four years--unless I want to add carrying some kind of filter (over glasses or over screen) to my daily routine, is there any other way to globally adjust the light spectrum emitted from my iPad & iPhone at night? I see several apps to darken browsers, and already use sepia background for my reader apps, but is there anything that can adjust the lights to redder at night, and back to whiter/bluer during the day?

Ideally a simple slider light the bright/dark control would be available to do this.

Guessing the answer is no, I'm sending feedback to Apple. It would likely be a very simple thing to implement, and if enough of us request the same thing, maybe we can get it done. Android can already do it.