Examine source code of Subflix

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "version": "1.2.1",
  "icons": {
    "16": "icons/icon16x.png",
    "32": "icons/icon32x.png",
    "48": "icons/icon48x.png",
    "96": "icons/icon96x.png",
    "128": "icons/icon128x.png",
    "256": "icons/icon256x.png"
  },
  "default_locale": "en",
  "description": "__MSG_extensionDescription__",
  "content_scripts": [
    {
      "matches": [
        "*://*.netflix.com/*"
      ],
      "js": [
        "subflix.js"
      ]
    }
  ],
  "options_ui": {
    "page": "options.html"
  },
  "permissions": [
    "storage"
  ],
  "applications": {
    "gecko": {
      "id": "subflix@example.org"
    }
  }
}