Examine source code of Quiet Tabs Manager

{
  "manifest_version": 2,
  "name": "Quiet Tabs Manager",
  "version": "1.0",
  "description": "Automatically mute and manage inactive tabs.",
  "permissions": [
    "tabs",
    "storage",
    "webNavigation"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{265fc58a-c90c-4f91-bc31-1af34256ad08}"
    }
  }
}