var MutationObserver = window.MutationObserver || window.WebKitMutationObserver || window.MozMutationObserver;

    var watch = $('.message-list');

    var observer = new MutationObserver(function (mutations) {
        var mutation = mutations[mutations.length - 1];
        if (mutation.type === "childList") {
            try {
                var latestMessageContent = watch[0].children[watch[0].children.length - 1].querySelector(".message .bubble.bubble-text .message-text span.selectable-text").textContent.toString();