Most im posting are cropped for widescreen already. To view I use Virtual Desktop and the half sbs option on the left of the floating menu when in environment. using that any program that stretches it to fullscreen horizontally will work (regardless if cropped).

For non cropped I prefer using wallpaper engine for the mouse paralax feature. unlink X and Y axis and only paralax Y axis and you can have the full pic despite vertical as your wallpaper. all audio responsive add ons still work as long as you can position a copy for both eyes.

To make your own I rec Owl3D (https://www.owl3d.com/) for images, no need to crop. Free for most features and runs locally.

For video (and cropped images) I mostly use IW3

I prefer working with videos so I will link my video wallpaper dumps as I get them uploaded