Examine source code of Tab Reminders

{
  "manifest_version": 2,
  "name": "Tab Reminders",
  "version": "1.0",
  "description": "Automatically sends notifications if a tab has been open for too long but not used. Users can set a maximum idle time, and the extension will remind or close the tab if necessary.",
  "permissions": [
    "tabs",
    "notifications",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icons/icon48.png",
      "96": "icons/icon96.png"
    }
  },
  "icons": {
    "48": "icons/icon48.png",
    "96": "icons/icon96.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9e5e5104-4e1c-4604-81e9-d8af4707cc66}"
    }
  }
}