Examine source code of Fingerprint Biometrics Reader

{
  "applications": {
    "gecko": {
      "id": "fingerprint_reader@maxgontijo.com.br"
    }
  },
  "manifest_version": 2,
  "name": "Fingerprint Reader",
  "version": "1.1.2",
  "description": "Supports developers to include fingerprint readers to web application.",
  "icons": {
    "48": "icons/fingerprint.svg"
  },
  "author": "Max Gontijo de Oliveira",
  "homepage_url": "https://maxopala.github.io/fingerprint-reader-web-extension",
  "permissions": [
    "webRequest",
    "tabs",
    "activeTab",
    "webNavigation",
    "nativeMessaging",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content_scripts/js/verify_suport.js"
      ]
    }
  ],
  "browser_action": {
    "default_icon": "icons/fingerprint.svg",
    "default_title": "Fingerprint Reader - Test",
    "default_popup": "browser_action/app.html"
  },
  "web_accessible_resources": [
    "web_accessible_resources/mgo-fingerprint-reader.js"
  ]
}