Examine source code of WhatFont

{
  "manifest_version": 2,
  "name": "WhatFont",
  "version": "1.0.0",
  "description": "Identify fonts used on web pages.",
  "author": "WhatFont Community",
  "browser_action": {
    "default_title": "WhatFont",
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "meyam.d.la.l.90.8@gmail.com",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}