Examine source code of Focus Breathing

{
  "manifest_version": 2,
  "name": "Focus Breathing",
  "version": "1.0.0",
  "description": "Practice guided breathing exercises to reduce stress and improve focus with customizable timing and visual cues.",
  "permissions": [
    "storage"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Focus Breathing",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  },
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{8a65da49-b8f8-4cde-bae7-3882571afd64}"
    }
  }
}