Twitter Keyword Highlight for Fluid

// ==UserScript==
// @name        Highlight
// @namespace   http://fluidapp.com
// @description What does this do?
// @include     *
// @author      Someone
// ==/UserScript==

(function () {
    if (window.fluid) {
        setInterval(function () {
        highlightWord(document.body,'WordPress');
        highlightWord(document.body,'Minnesota');
        highlightWord(document.body,'Mac');
        highlightWord(document.body,'free');
        highlightWord(document.body,'Free');
        highlightWord(document.body,'Apple');

        function highlightWord(root,word){
          textNodesUnder(root).forEach(highlightWords);

          function textNodesUnder(root){
            var walk=document.createTreeWalker(root,NodeFilter.SHOW_TEXT,null,false),
                text=[], node;
            while(node=walk.nextNode()) text.push(node);
            return text;
          }

          function highlightWords(n){
            for (var i; (i=n.nodeValue.indexOf(word,i)) > -1; n=after){
              var after = n.splitText(i+word.length);
              var highlighted = n.splitText(i);
              var span = document.createElement('span');
              span.className = 'highlighted';
              span.appendChild(highlighted);
              after.parentNode.insertBefore(span,after);
            }
          }
        }
    }, 10000)

    }
})();