Examine source code of Interval Training Timer

{
  "manifest_version": 2,
  "name": "Interval Training Timer",
  "version": "1.0",
  "description": "A customizable interval timer for managing your workout sessions.",
  "icons": {
    "48": "icons/interval-timer-icon-48.png"
  },
  "permissions": [],
  "browser_action": {
    "default_icon": "icons/interval-timer-icon-48.png",
    "default_popup": "popup.html",
    "default_title": "Interval Timer"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{c6bbeae0-db0a-45e6-8684-4ce71a3d2b35}"
    }
  }
}