Examine source code of Ugly Email

{
  "name": "Ugly Email",
  "short_name": "Ugly Email",
  "version": "4.1.2",
  "description": "Get Back Your Email Privacy, Block Email Tracking.",
  "author": "OneClick Lab",
  "homepage_url": "http://uglyemail.com",
  "manifest_version": 2,
  "content_security_policy": "script-src 'self' 'unsafe-eval'; object-src 'self'",
  "content_scripts": [
    {
      "matches": [
        "https://mail.google.com/*"
      ],
      "js": [
        "loader.js"
      ],
      "run_at": "document_end"
    }
  ],
  "web_accessible_resources": [
    "uglyemail.js"
  ],
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "https://mail.google.com/*",
    "*://*.googleusercontent.com/proxy/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "icons": {
    "16": "icons/Icon-16.png",
    "48": "icons/Icon-48.png",
    "128": "icons/Icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{5048fdff-56a3-4108-bc52-b8a03fc343ba}"
    }
  }
}