Moon reader for Android has a built-in feature to set extra-low brightness using something like a full-screen gray/alpha overlay. That, plus white text on a ful

Moon reader for Android has a built-in feature to set extra-low brightness using something like a full-screen gray/alpha overlay. That, plus white text on a full-screen black background, makes for an extremely dim screen. It only works for reading ebooks (or whatever you can open in the app), which IMO is a huge benefit. I don't want to be scrolling nonsense websites in bed, but I do think a smartphone ebook reader is the least-bright, most comfortable and most ergonomic way to read in bed.