Examine source code of TimezoneEditor

{
  "manifest_version": 2,
  "name": "TimezoneEditor",
  "version": "1.0.0",
  "description": "a simple tool to help you edit timezone value",
  "browser_action": {
    "default_icon": "images/icon-32.png",
    "default_popup": "popup.html"
  },
  "permissions": [
    "storage",
    "webNavigation",
    "<all_urls>",
    "*://*/*"
  ],
  "icons": {
    "16": "images/icon-16.png",
    "32": "images/icon-32.png",
    "48": "images/icon-48.png",
    "96": "images/icon-96.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "web_accessible_resources": [
    "popup.html"
  ]
}