Freeware - iZotope Ozone Imager VST Plug-in

https://www.izotope.com/en/products/master-and-deliver/ozone/ozone-imager.html

Ozone Imager is a FREE stereo imaging plug-in for your DAW or NLE. Born from Ozone 8’s legendary Imaging technology, Ozone Imager can narrow or widen your stereo image with simple controls, stunning visuals, and incredible sound.