Examine source code of Internet Speed Fan

{
  "manifest_version": 3,
  "short_name": "Internet Spee Fan",
  "name": "Internet Speed Fan",
  "description": "A quick, accurate and aesthetically pleasing way to know your internet speed & status",
  "version": "1.3.1",
  "action": {
    "default_popup": "index.html",
    "default_title": "Internet Speed Fan",
    "default_icon": "litelogo.png"
  },
  "icons": {
    "16": "litelogo.png",
    "48": "litelogo.png",
    "128": "litelogo.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "internetspeedproject@obayomibrothers.com",
      "strict_min_version": "58.0"
    },
    "safari": {
      "strict_min_version": "14",
      "strict_max_version": "20"
    }
  }
}