Examine source code of Forex Time

{
  "manifest_version": 2,
  "name": "Forex Time",
  "description": "Find out forex market hours at a glance.",
  "version": "1.1.0",
  "icons": {
    "48": "icon-48.png",
    "128": "icon-128.png"
  },
  "browser_action": {
    "default_icon": {
      "19": "icon-19.png",
      "38": "icon-38.png"
    },
    "default_popup": "popup.html"
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": false,
    "open_in_tab": true
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "web_accessible_resources": [
    "antd.min.css",
    "antd.dark.min.css"
  ],
  "permissions": [
    "storage"
  ],
  "applications": {
    "gecko": {
      "id": "extension@forexTime"
    }
  }
}