Twinkle Tray is described as 'Enables brightness control on external displays in Windows 10 & 11. Even th Windows is capable of adjusting the backlight on most monitors, it doesn't support external monitors natively' and is a Screen Dimmer in the system & hardware category. There are more than 25 alternatives to Twinkle Tray for a variety of platforms, including Windows, Mac, Linux, openSUSE and Flathub apps. The best Twinkle Tray alternative is Solace. It's not free, so if you're looking for a free alternative, you could try Monitorian or MonitorControl. Other great apps like Twinkle Tray are Dimmer, Lunar, DisplayBuddy and Brightintosh.