Ruby Switch от Steve A. Doria

Conveniently sets the Visibility attribute of RT or ruby text HTML elements to "hidden". When pinned to the toolbar, allows using a toolbar button to toggle the visibility of furigana or other pronunciation aid on web pages that use the HTML Ruby Markup Extensions.

The following is a sampling of sites that work with Ruby Switch:

• nhk.or.jp
• mainichi.jp
• jisho.org
• matcha-jp.com
• tadoku.org