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@Hadron , I experimented with a few apps before 'dimmers' and 'nightlights' became standard fair, built in features on our devices.
As he says, they are annoying.
Well, they were annoying.
The built in ones are great, although sometimes it comes on while I am using the device (it is set to automatically do so) and that is sometimes disconcerting if I am in a well lit area, or at least until my eyes get used to it.
There are a couple of apps that I have tried that seem to me to be much better than the rest.
Not really sure how much blue light is being filtered, they seem to work best as dimmers in general.
One is older, and one is newer.
The newer one, Night Screen, is my favorite, if you have to use a third party app for this purpose.
https://f-droid.org/en/packages/giraffine.dimmer/
https://f-droid.org/en/packages/info.papdt.blackblub/
As far as helping me get to sleep, I really can't tell.
I have heavily modified my sleeping accomodations to my liking.
As such, once you lay down, it immediately bevomes difficult to stay alert and awake.
So with or without any light filter, without a high dose of caffiene, a purpose, and some effort on my part, staying awake while in my 'bed' is really not an option.
Any time I am sitting upright and using a device, my back quickly begins to hurt (if it didn't already) and I soon migrate to the 'bed'.
What I can say is that I like the dimming effect, when used sparingly.
Basically I forget that I am using it hntil it goes off automatically, or I turn it off, and then I notice the difference.
I do think that it makes a small device easier to read things on, especially for long reads, simply by making it more comfortable to stare at.