Examine source code of Screamer

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "version": "1.1",
  "default_locale": "en",
  "author": "Pavel 'nxblnd' Egorov",
  "description": "__MSG_extensionDescription__",
  "permissions": [
    "activeTab",
    "storage"
  ],
  "background": {
    "scripts": [
      "src/browser-polyfill.js",
      "src/background.js"
    ]
  },
  "content_scripts": [
    {
      "js": [
        "src/browser-polyfill.js",
        "src/screamer.js"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "web_accessible_resources": [
    "resources/soundboard/antivirusPig.ogg",
    "resources/soundboard/civilProtection.ogg",
    "resources/soundboard/alarmClock.ogg"
  ],
  "options_ui": {
    "page": "src/options/options.html",
    "browser_style": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "screamer-addon@example.com"
    }
  }
}