HazeOver

About

HazeOver shades the windows sitting behind the active one, so the thing you are reading or typing in is the only bright part of the screen. The dimming level is adjustable from the menu bar or with a two-finger scroll over the menu bar icon, and it can highlight either the single focused window or every window belonging to the active app, with a short animation when focus changes so the eye can follow. It can be toggled with a hotkey and started at login, and it runs for hours without getting in the way, which is why it is still one of the oldest focus utilities on the Mac. It is a one-time purchase on the Mac App Store, with a free trial build from the developer's site. It needs macOS 12 or later.