Examine source code of Bookmark Pivot

{
  "manifest_version": 2,
  "name": "Bookmark Pivot",
  "description": "Rethinking the humble bookmark",
  "version": "0.0.4",
  "icons": {
    "16": "img/icon_16.png",
    "24": "img/icon_24.png",
    "32": "img/icon_32.png",
    "128": "img/icon_128.png"
  },
  "permissions": [
    "activeTab",
    "bookmarks",
    "storage",
    "tabs",
    "<all_urls>"
  ],
  "browser_action": {
    "default_icon": "img/icon_32.png",
    "default_title": "Bookmark Pivot",
    "default_popup": "popup.html"
  }
}