Examine source code of QualiSign

{
  "description": "QualiSign",
  "manifest_version": 2,
  "name": "QualiSign",
  "version": "1.0.0.5",
  "icons": {
    "48": "icons/icone-qualisign-png-48x48.png"
  },
  "applications": {
    "gecko": {
      "id": "ususerv@qualisign.com.br",
      "strict_min_version": "50.0"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "icons/icone-qualisign-png-48x48.png",
    "default_title": "QualiSign"
  },
  "content_scripts": [
    {
      "all_frames": true,
      "js": [
        "scripts/content.js"
      ],
      "matches": [
        "http://*/*",
        "https://*/*",
        "file://*/*"
      ]
    }
  ],
  "permissions": [
    "nativeMessaging",
    "activeTab",
    "tabs",
    "storage"
  ]
}