Examine source code of World Radio

{
  "manifest_version": 2,
  "name": "World Radio",
  "version": "1.0",
  "description": "Listen to more than 50,000 radio stations worldwide.",
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_title": "Worldwide Radio",
    "default_icon": {
      "64": "icon64.png",
      "128": "icon128.png"
    },
    "default_popup": "popup.html"
  },
  "icons": {
    "64": "icon64.png",
    "128": "icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a5f12cc3-af4a-45c2-acf1-3af77c2fbe9a}",
      "strict_min_version": "114.0"
    }
  }
}