It automatically manages Windows mouse acceleration, also known as "enhanced pointer precision".
It's handy if you prefer to keep Windows mouse acceleration enabled on the desktop, but not in legacy Windows games that don't use raw input to bypass the Windows mouse filters.
The program runs in the background and detects if the native Windows cursor becomes hidden. If hidden, mouse acceleration will be disabled. When visible, it will be enabled.
To set mouse acceleration manually, open the mouse properties from the Control Panel and navigate to the Pointer Options tab. Toggling "Enhance pointer precision" enables mouse acceleration when turned on. It's on by default.