Examine source code of NFeApp

{
  "name": "__MSG_appName__",
  "description": "__MSG_appDescription__",
  "version": "1.0.1resigned1",
  "short_name": "__MSG_appShortName__",
  "manifest_version": 2,
  "default_locale": "pt_BR",
  "icons": {
    "16": "images/icon-16.png",
    "128": "images/icon-128.png"
  },
  "background": {
    "scripts": [
      "scripts/background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "19": "images/icon-19.png",
      "38": "images/icon-38.png"
    },
    "default_title": "__MSG_browserActionTitle__",
    "default_popup": "pages/popup.html",
    "default_area": "navbar"
  },
  "content_scripts": [
    {
      "matches": [
        "http://notaparana.pr.gov.br/*",
        "https://notaparana.pr.gov.br/*",
        "http://*.notaparana.pr.gov.br/*",
        "https://*.notaparana.pr.gov.br/*",
        "http://nfeapp.com.br/*",
        "https://nfeapp.com.br/*",
        "http://*.nfeapp.com.br/*",
        "https://*.nfeapp.com.br/*"
      ],
      "js": [
        "scripts/contentscript.js"
      ],
      "run_at": "document_end",
      "all_frames": false
    }
  ],
  "permissions": [
    "activeTab",
    "cookies",
    "sessions",
    "storage",
    "webNavigation",
    "webRequest",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "nfeappfirefox@nfeapp.com.br",
      "strict_min_version": "57.0"
    }
  }
}