Nope, not spam. I’ve uninstalled it and replaced it with the Stackable plugin, and that seems to work fine. I’m running the current version of WordPress – 5.6.1 – and the current version of chrome 88.0.4324.109 (Official Build) (64-bit). I’ve now removed you plugin, but it was the one I downloaded yesterday from the plugin search bar in wordpress.
Nope – it is there – I added the recommended CSS in the customizer Additional CSS section. The other pages shows how it looks without the special classes.