Examine source code of Reading Progress Bar is

{
  "manifest_version": 2,
  "name": "Reading Progress Bar",
  "version": "1.0",
  "description": "Hiển thị thanh tiến trình khi cuộn trang",
  "permissions": [
    "tabs"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "style.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "icons": {
    "16": "icon.png"
  },
  "applications": {
    "gecko": {
      "id": "reading-progress-bar-f2e110d3@example.com"
    }
  }
}