Examine source code of TabSoundTracker

{
  "manifest_version": 2,
  "name": "TabSoundTracker",
  "version": "1.0",
  "description": "Track and manage tabs that are playing sound.",
  "icons": {
    "64": "icons/icon64.png",
    "128": "icons/icon128.png"
  },
  "browser_action": {
    "default_icon": "icons/icon64.png",
    "default_title": "TabSoundTracker",
    "default_popup": "popup.html"
  },
  "permissions": [
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{1cc7a3e1-1384-47e5-b2ef-622b604786ec}",
      "strict_min_version": "114.0"
    }
  }
}