MarkerOn

MarkerOn is a small screen annotation tool for Windows and macOS. You press a hotkey and can instantly draw, highlight and annotate anywhere on your desktop, which is handy for demos, teaching, meetings and screen recordings. It runs in the system tray and shows no window until you need it.

Press Ctrl+Shift+D, or Command+Shift+D on macOS, to enter annotation mode, then use number keys or V to choose tools. Eleven tools are listed, including select, pen, highlighter, laser, arrow, rectangle, ellipse, line, eraser, text and stamp. A click-through mode lets you interact with the apps underneath while annotations stay visible, a marquee selection supports batch editing, and a toolbar appears with the Space key. A portable Windows build keeps its configuration beside the executable.

The tool is built with Tauri, Rust, Vue 3 and TypeScript, has an installer of roughly 1.5 MB, and states that it has no extra daemons or telemetry. It is licensed under MIT, with downloads on GitHub Releases and the Microsoft Store. It suits presenters, teachers and streamers who annotate their screens.