Very nice and clever. Excellent as a reminder. Unfortunately it is an old addon. Some characters are changed in the latest version of Firefox: https://support.mozilla.org/en-US/kb/awesome-bar-search-firefox-bookmarks-history-tabs#w_changing-results-on-the-fly

Good, but please, make the characters clickable.

It's fun, useful but lacks a sense of presence, it will be better if placed on the page actions.