Examine source code of T Twenty

{
  "background": {
    "persistent": false,
    "scripts": [
      "js/background.js"
    ]
  },
  "browser_action": {
    "default_icon": "images/icon38.png",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "js": [
        "js/jquery.js",
        "js/jquery-ui.js",
        "js/screenshot.js"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "description": "Capture web pages, annotate right inside your browser. | スクリーンショットとお絵かきと保存とこれ一つで。画面をキャプチャーして、線・矢印・矩形・文字などの描き込みを行いJPEG形式で保存することが可能です。",
  "icons": {
    "32": "images/icon32.png",
    "48": "images/icon48.png",
    "128": "images/icon128.png"
  },
  "key": "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEApFkmJzgwTW0Xg3ZEOKDy5pKrM+DPIhzalGrODjg5kq9w2NHRyrqwT7zN8Bd2zHktJVNan/hT8qLgGJYJmwHEnIdV/soNmmMKPlKn863ZGqgMSyTrZ/Ya+UDnKhSKzNvRZmklm+6aNIJCgsL2PpRpORpVgsms3KO0Ea5rp4upVpbhVta2wkJIYjERK/jbcu2b3d0hnnLwZ/GV/E4C47VyUaXBgsnpySKOHWr+1gkVcfOYkVXnDBhXWJen+Eg1dzAIZHOXkuxuveksB9nSbB2r82auJNbINGbXQVs7Y42c59Ai108wFJsunsre5ITiy2mkYs6pn3q2p7pPdmQMPvZbMwIDAQAB",
  "manifest_version": 2,
  "name": "Webpage Capture and Paint",
  "offline_enabled": true,
  "permissions": [
    "<all_urls>",
    "contextMenus",
    "tabs",
    "activeTab",
    "storage",
    "unlimitedStorage",
    "background",
    "http://*/*",
    "https://*/*"
  ],
  "update_url": "https://clients2.google.com/service/update2/crx",
  "version": "1.1.5",
  "web_accessible_resources": [
    "images/*.svg",
    "css/jqueryui.css",
    "css/images/*.png"
  ]
}