Tool wanted : highlighter for webpage

Hi,

Am searching for a brower addon that can highlight a content on the fly.
Ex: i set up some pattern, like: /(post|write)+ (1|a)+ (comment|post)+/i
If that text in page content, then "post a comment"is highlighted...
Any idea?

https://addons.mozilla.org/en-US/firefox/addon/stylish/
https://chrome.google.com/webstore/detail/stylish/fjnbnpbmkenffdnngjfgmeleoegfcffe