@Teasday
Oh I already do that with my device brightness, the problem is the device brightness not going low enough. Thus I have to use third party solutions like the overlay to read in the dark. Even with device brightness as low as it can get, due to the black and white contrast of manga it is...
I think a cool feature that could be added in terms of UI is a night mode for the site. Night modes for manga sites dont usually work too well because manga is black and white but you could implement a setting for an overlay over the manga image that could darken the image similar to how shades...