Examine source code of MyDirections

{
  "manifest_version": 2,
  "name": "__MSG_extName__",
  "short_name": "__MSG_extName__",
  "version": "2.6.7.2",
  "description": "__MSG_description__",
  "default_locale": "en",
  "homepage_url": "https://my-directions.com",
  "author": "my-directions.com",
  "browser_action": {
    "default_icon": "images/icon/icon48.png",
    "default_title": "__MSG_extName__",
    "default_popup": "popup/index.html"
  },
  "chrome_url_overrides": {
    "newtab": "/dist/index.html"
  },
  "icons": {
    "16": "images/icon/icon16.png",
    "32": "images/icon/icon32.png",
    "48": "images/icon/icon48.png",
    "128": "images/icon/icon128.png"
  },
  "background": {
    "scripts": [
      "js/misc.js",
      "js/background.js",
      "popup/gmail/js/jquery.min.js",
      "popup/gmail/js/config.js",
      "popup/gmail/js/addressparser.js",
      "popup/gmail/js/gmail.js",
      "popup/gmail/js/account.js",
      "popup/gmail/js/background.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "all_frames": false,
      "js": [
        "popup/gmail/tabletView.js",
        "js/content_script.js"
      ],
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_start"
    }
  ],
  "permissions": [
    "bookmarks",
    "history",
    "contextMenus",
    "tabs",
    "https://*.my-directions.com/",
    "https://mail.google.com/",
    "notifications"
  ],
  "web_accessible_resources": [
    "popup/gmail/gmail.html",
    "popup/gmail/tabletView.css"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{7313aced-ab7c-40fb-bf3a-115e91ba6c2a}"
    }
  }
}