Examine source code of Sound Tab Switcher

{
  "manifest_version": 2,
  "name": "Sound Tab Switcher 1.0",
  "version": "1.0",
  "description": "Uma extensão para mudar para a aba que reproduz som, Exceto Youtube",
  "permissions": [
    "tabs",
    "activeTab"
  ],
  "icons": {
    "16": "icon16.png",
    "32": "icon32.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{69f02ff1-be0a-4b60-b22f-87800bc3fc84}"
    }
  }
}