Examine source code of Tab Sounds

{
  "manifest_version": 2,
  "name": "Tab Sounds",
  "version": "1.0",
  "description": "Redă sunete când deschizi sau închizi taburi.",
  "permissions": [
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "web_accessible_resources": [
    "window-new.wav",
    "window-close.wav"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{a7e865ac-8856-4bdc-9a5f-3a884c651267}"
    }
  }
}