Examine source code of TipType Typing Practice

{
  "manifest_version": 3,
  "name": "TipType Typing Practice",
  "version": "1.9.1",
  "description": "Turn any site into a typing practice, any paragraph into a typing test. Master your touch typing skills on pages you want to read.",
  "browser_specific_settings": {
    "gecko": {
      "id": "contact@tiptype.com",
      "strict_min_version": "109.0"
    }
  },
  "icons": {
    "16": "images/icon-16.png",
    "32": "images/icon-32.png",
    "48": "images/icon-48.png",
    "128": "images/icon-128.png"
  },
  "action": {
    "default_title": "TipType Typing Practice",
    "default_icon": "images/icon-48.png"
  },
  "data_collection_permissions": {
    "required": [
      "none"
    ]
  },
  "permissions": [
    "storage",
    "activeTab"
  ],
  "host_permissions": [
    "http://tiptype.com/*",
    "https://tiptype.com/*"
  ],
  "content_scripts": [
    {
      "js": [
        "scripts/pre-start.js"
      ],
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "run_at": "document_start"
    },
    {
      "js": [
        "scripts/tiptype.js",
        "scripts/start.js"
      ],
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "run_at": "document_idle"
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "assets/*",
        "scripts/extension-load.js"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "background": {
    "scripts": [
      "scripts/background.js"
    ]
  }
}