Examine source code of SIT 3DA CA WEB Client 2

{
  "manifest_version": 2,
  "version": "2.0.5",
  "name": "SIT 3DA CA WEB Client 2",
  "description": "Extension for signing documents in browser",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*",
        "file://*/*"
      ],
      "js": [
        "content.js"
      ],
      "all_frames": true,
      "run_at": "document_start"
    }
  ],
  "permissions": [
    "nativeMessaging"
  ],
  "icons": {
    "16": "icons/icon16.png",
    "24": "icons/icon24.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "64": "icons/icon64.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "sign@sit.company",
      "strict_min_version": "63.0"
    }
  }
}