Or just use the screensavers hack by itself...
In fact, the hack depends on and extracts cover images to [userstore]/linkss/cover_cache/cover_${ASIN}.png (on my KT at least), so I would venture to say this plugin will not actually transfer any useful images.
...
Come to think of it... some MOBI/AZW3 do not have covers, or MOBI can't really have the cover updated without a full reconversion
so the hack won't ever see your calibre-updated cover metadata. That being the case, I can see why it might be nice if this plugin was able to generate the cover_cache from calibre's metadata.