meowcount.js

document.body.appendChild(document.createElement('script')).src='https://rawgit.com/tommoor/tinycon/master/tinycon.min.js';
document.body.appendChild(document.createElement('script')).src='//cdnjs.cloudflare.com/ajax/libs/lodash.js/2.4.1/lodash.js';

// select the target node
var target = document.querySelector('#chat-list');

var count = 0;
// create an observer instance
var observer = new MutationObserver(function(mutations) {
  var message = mutations[0].addedNodes[0].getElementsByTagName('p')[0].innerHTML
  _.each(message.split(' '), function (word) {
    if (word === 'meow') {
      console.log(word);
      count++;
      Tinycon.setBubble(count);
    }
  });
});

// configuration of the observer:
var config = { attributes: true, childList: true, characterData: true };

// pass in the target node, as well as the observer options
observer.observe(target, config);