Night reading mode works great in apps for reading books like the Kindle eBook app. But not all book apps include this feature. Night reading mode darkens the background of the screen while providing white or light text. Users will want to do this while reading in a dark room so the backlit display doesn’t disturb others in bed at night. You can also use it for typing in a room where someone is presenting at work with the lights off. Users can turn on some kind of temporary nighttime reading mode using iPhone Accessibility features. This will change the entire OS UI on iPhone or iPad as in the image below. We can set this feature to turn on using the Home button via the iPad’s Settings.
See other great iOS tips, including How to Set Up Multiple Reminders Lists on iPhone and How to Set Up iMessage on iPhone and iPad.
Steps to Unlock iOS Version of Night Reading Mode
Use the Accessibility Triple-click Home feature to turn on a temporary nighttime reading mode
Open the Settings App on iPhone or iPad. Open it and scroll down and tap it to open it.

Turn on Accessibility in the Settings app under General
Now swipe down to the bottom of the screen and tap the button. This shows a screen with options for what the phone can do when a user quickly taps the Home button three times. They include:
After setting the above feature, the user can use his iPad using the normal color scheme. When the user needs to turn on this temporary night reading mode, the person will quickly tap the Home button three times. This activates the mode, making white backgrounds black and darker foreground text white or light colors. As a result, other people in the dark room will not disturb the bright iPad or iPhone screen.

Compare this image with the first image above.
Thanks to the OliveTree team, makers of one of the best Bible reading apps, for this tip.