UPDATE: Introducing Splits
I recently added splits to 360photo-to-video.com. Splits are 2 interactive images in 360-degree format separated horizontally or vertically. Like so:
They can be used standalone or embedded with iframe, similar to loops (as described here Convert 360 video into interactive GIF - #10 by eGene).
Great way to show your before and after pictures compared side-to-side!