Examine source code of privacy++

{
  "manifest_version": 2,
  "name": "privacy++",
  "version": "1.0",
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://stackoverflow.com/*",
        "https://askubuntu.com/*"
      ],
      "js": [
        "script/stackoverflow.js"
      ]
    }
  ],
  "browser_action": {
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "privacy@plusplus"
    }
  }
}