It's just a command-line utility that can change resolution and refresh rate of your monitor.
Usage:
windisplaymode list <display>
Print a list of available modes for the specified display
windisplaymode set <display> <mode>
Change display mode
Examples:
windisplaymode set 0 1920x1080
Change resolution of display 0 (first display) to 1920 (width) by 1080 (height) pixels
windisplaymode set 0 1920x1080x32
Change resolution of display 0 to 1920x1080 with 32-bit colors
windisplaymode set 0 1920x1080@60
Set both resolution and refresh rate (60 Hz)
windisplaymode set 0 @144
Change refresh rate to 144 Hz keeping the same resolution and color depth