Examine source code of Integrity VPN Checker

{
  "manifest_version": 2,
  "name": "Integrity VPN Checker",
  "version": "1.1",
  "description": "Shows a green thumbs up if you're connected via Integrity VPN",
  "icons": {
    "16": "images/icon-16.png",
    "48": "images/icon-48.png",
    "128": "images/icon-128.png"
  },
  "background": {
    "scripts": [
      "scripts/background.js"
    ]
  },
  "permissions": [
    "https://integrity.st/*"
  ],
  "browser_action": {
    "default_icon": "images/icon-16.png",
    "default_title": "Integrity VPN Checker"
  }
}