Examine source code of Quiet Tabs

{
  "manifest_version": 2,
  "name": "Quiet Tabs",
  "version": "1.0.4",
  "description": "Mute or unmute every tab with one click.",
  "permissions": [
    "tabs",
    "storage"
  ],
  "browser_action": {
    "default_icon": {
      "16": "icons/volume_on_16.png",
      "32": "icons/volume_on_32.png",
      "48": "icons/volume_on_48.png",
      "128": "icons/volume_on_128.png"
    },
    "default_title": "Mute All Tabs"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "48": "icons/volume_on_48.png",
    "128": "icons/volume_on_128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "quiet-tabs@example.com",
      "strict_min_version": "91.0"
    }
  }
}