Examine source code of Network Ping Checker

{
  "manifest_version": 2,
  "name": "Network Speed & Ping Checker",
  "version": "1.0",
  "description": "Quickly measure your internet download speed and ping directly in a browser tab without visiting external sites.",
  "browser_action": {
    "default_title": "Speed & Ping Checker",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icon.png",
      "48": "icon.png",
      "128": "icon.png"
    }
  },
  "permissions": [
    "activeTab",
    "https://download.thinkbroadband.com/*",
    "https://www.cloudflare.com/*",
    "https://raw.githubusercontent.com/*"
  ],
  "icons": {
    "16": "icon.png",
    "48": "icon.png",
    "128": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{4c5111fd-4454-43f8-96eb-3745adb4faea}"
    }
  }
}