Examine source code of Tab Loading Checker

{
  "manifest_version": 2,
  "name": "Tab Loading Checker",
  "version": "1.1",
  "description": "Check if there are tabs still loading.",
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "browser_action": {
    "default_icon": {
      "64": "icon.png"
    },
    "default_title": "Tab Loading Checker",
    "default_popup": "popup.html"
  },
  "permissions": [
    "tabs",
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{282768f5-bbe0-4869-a98a-7cb3ed707a1f}"
    }
  }
}