Examine source code of TextOptimizer

{
  "manifest_version": 2,
  "name": "TextOptimizer",
  "description": "Writing Assistant Tool.",
  "version": "2.0",
  "homepage_url": "https://textoptimizer.com",
  "offline_enabled": false,
  "minimum_chrome_version": "88.0.0",
  "icons": {
    "16": "i/textoptimizer_icon16.png",
    "48": "i/textoptimizer_icon.png",
    "128": "i/textoptimizer_icon.png"
  },
  "browser_action": {
    "default_icon": "i/icon.png"
  },
  "permissions": [
    "storage",
    "tabs",
    "scripting",
    "activeTab",
    "cookies"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "backgroundServiceWorker.js"
    ],
    "persistent": false
  },
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content_main.js"
      ],
      "run_at": "document_end"
    },
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "js/jquery-3.4.1.min.js"
      ],
      "all_frames": true,
      "match_about_blank": true,
      "run_at": "document_end"
    },
    {
      "matches": [
        "<all_urls>"
      ],
      "css": [
        "css/jquery-ui.css",
        "css/textoptimizer_widget.css"
      ],
      "js": [
        "js/jquery-ui.js",
        "content_main.js"
      ],
      "run_at": "document_end"
    }
  ],
  "web_accessible_resources": [
    "textoptimizer.html",
    "i/icon.png",
    "i/*.png",
    "i/*.gif",
    "i_extension/*.png",
    "i_extension/*.gif"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{e662c469-08c9-4c5a-a463-96ff15506033}"
    }
  }
}