This App simply allows you to choose two different Wallpapers for your phone - one for the regular "Light" mode and one for Dark Mode. Then every time the System theme changes, so does your Wallpaper - just with certain Wallpapers in iOS13 or iOS14.

The App works by using a customizable a Live-Wallpaper. It also allows you to easily share your Wallpapers from other Apps (like the Gallery) with Darkinator.