Examine source code of Mate Tools

{
  "manifest_version": 3,
  "name": "Mate Tools",
  "version": "2.0.0",
  "description": "Quickly access mate.tools for the collection of free online tools to help streamline your productivity and workflow.",
  "permissions": [
    "idle",
    "storage"
  ],
  "browser_action": {
    "default_popup": "index.html",
    "default_icon": {
      "16": "assets/images/icon16.png",
      "32": "assets/images/icon32.png",
      "48": "assets/images/icon48.png",
      "128": "assets/images/icon128.png"
    }
  },
  "background": {
    "scripts": [
      "assets/js/background.js"
    ]
  },
  "icons": {
    "16": "assets/images/icon16.png",
    "32": "assets/images/icon32.png",
    "48": "assets/images/icon48.png",
    "128": "assets/images/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{371a381a-d635-4cc0-9afc-d14a9b4e9560}"
    }
  }
}