Hej Stylus! is currently a application, and there is no official version for Windows .

The developer explicitly lists macOS as the only supported operating system, with features designed for OS X 10.11 and later. While it is highly regarded for its global pen stabilization and ruler tools on Mac, Windows users must look to alternatives for similar system-wide functionality. Best Windows Alternative: Lazy Nezumi Pro Lazy Nezumi Pro

is widely considered the Windows equivalent of Hej Stylus!. It provides nearly identical—and often more extensive—features for Windows users: