Tampermonkey script that adds a navigation button for getting to your watch later playlist easily

youtube-watchlater-button.user.js

// ==UserScript==
// @name         Youtube WatchLater Button
// @namespace    http://nkmathew.net
// @version      0.2.0
// @description  Adds a button for getting to your watch later playlist easily
// @icon         http://youtube.com/favicon.ico
// @icon64       http://youtube.com/favicon.ico
// @author       nkmathew
// @match        https://www.youtube.com/*
// @grant        none
// ==/UserScript==

(function() {
  'use strict';

  var downloadButton;
  var anchorText       = document.createElement('span');
  var button           = document.createElement('a');
  var buttonsContainer = document.createElement('span');
  var userMasthead     = document.getElementById('yt-masthead-user');
  var youtubeUrl       = encodeURIComponent(window.location);

  var downloaders = {
    savido  : 'http://www.savido.net/download?url=',
    keepvid : 'http://www.keepvid.com/?url=',
  };

  // Button text
  anchorText.innerText = 'Watch Later';
  anchorText.classList.add('yt-uix-button-content');

  // Watch Later button node
  button.href = '/playlist?list=WL';
  button.style.fontWeight = 'bold';
  button.style.height = '29px';
  button.style.marginLeft = '5px';
  button.classList.add('guide-watch-later-icon');
  button.classList.add('no-icon-markup');
  button.classList.add('play-all-icon-btn');
  button.classList.add('playlist-play-all');
  button.classList.add('spflink');
  button.classList.add('watchlater-button');
  button.classList.add('yt-uix-button');
  button.classList.add('yt-uix-button-default');
  button.classList.add('yt-uix-button-has-icon');
  button.classList.add('yt-uix-button-playlist-action');
  button.classList.add('yt-uix-button-size-default');
  button.classList.add('yt-uix-sessionlink');
  button.appendChild(anchorText);

  // Download button
  downloadButton = button.cloneNode(true);
  downloadButton.href = downloaders.keepvid + youtubeUrl;
  downloadButton.setAttribute('target', '_blank');
  downloadButton.innerText = 'Download Video';

  // Buttons Container
  buttonsContainer.style.right = '190px';
  buttonsContainer.style.top = '10px';
  buttonsContainer.style.position = 'absolute';
  buttonsContainer.appendChild(button);
  buttonsContainer.appendChild(downloadButton);

  userMasthead.parentNode.insertBefore(buttonsContainer, userMasthead.nextSibling);

})();