Greasy Fork is available in English.
Allows you to write Markdown in the notes, which will be rendered as HTML when the page loads.
https://www.wanikani.com/chat/api-and-third-party-apps/4024#post105996
Here are the supported markups:
#rad#text#/rad# = Radical highlight (blue)
#kan#text#/kan# = Kanji highlight (pink)
#voc#text#/voc# = Vocabulary highlight (purple)
#read#text#/read# = Reading highlight (black)
**text**, __text__ = bold
*text*, _text_ = italics
[Link Text](http://www.google.com) = hyperlinked text
 = image
~br~ = break (i.e. new line of text)
(Additional markup info: https://github.com/showdownjs/showdown)
