Examine source code of TST - Tab Sound Tracker

{
  "manifest_version": 2,
  "name": "TST - Tab Sound Tracker",
  "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": "TST",
    "default_popup": "popup.html"
  },
  "permissions": [
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{9a0f247a-20f5-4c5d-8846-74d33702383b}",
      "strict_min_version": "112.0"
    }
  }
}