Figma Dark UI
Interesting choice only revealing the screenshot when hovering the download button but no doubt a slick One Pager for Figma Dark UI – a Chrome Extension by Paper Tiger.
This website has unfortunately been redesigned or gone offline, so I have removed the direct link to it. The screenshot below hopefully preserved enough of the design but if you are really keen to inspect further, try this Archive.org link. FYI: the site was first featured on 12 March 2018.