Examine source code of Sign`A´Byte

{
  "manifest_version": 2,
  "name": "SignaByte",
  "version": "1.0.0",
  "description": "Digital signing extension for documents",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "activeTab",
    "storage",
    "nativeMessaging",
    "tabs",
    "*://localhost/*",
    "*://14.97.141.54/*",
    "*://*.keonext/*",
    "*://*.kkartkeonics/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://localhost/*",
        "*://14.97.141.54/*",
        "*://*.keonext/*",
        "*://*.kkartkeonics/*"
      ],
      "js": [
        "webextension-polyfill.js",
        "content.js"
      ],
      "run_at": "document_end"
    }
  ],
  "background": {
    "scripts": [
      "webextension-polyfill.js",
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "SignaByte",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "signabyte@signabyte.com",
      "strict_min_version": "79.0"
    }
  }
}