Dark mode was perhaps one of the most sought-after features in iOS & iPadOS 13 when it debuted in 2019. Even today, a substantial percentage of iOS and iPadOS 14 users continue to use dark mode right out of the box, and there are no signs of that changing with iOS & iPadOS 15 this Fall.
Many apps for iOS and iPadOS automatically adapt to your system dark mode settings in an effort to blend in with other parts of the operating system, but some apps require the user to switch to a dark mode-friendly user interface manually.