This is the simplest and slickest Markdown editor for Chrome. Works offline, allows to open/save files, and gets out of the way. More than 17 000 weekly users as of June 2018.
Also available as a web app with a smaller set of features.
WebGL experiment based on the League of Legends universe.
(Discontinued) Search My Posts allows you to search through your old Facebook posts, based on a keyword and the type of the post (music, videos, photos, links).
Craving Words is a Chrome extension that saves every word you search. You then receive a daily email containing all these words in order to really remember them.