Examine source code of CaptainA.co Helper Add-On

{
  "background": {
    "persistent": true,
    "page": "background.html"
  },
  "browser_action": {
    "default_icon": "images/icon32.png",
    "default_title": "CaptainA.co Helper Extension for AMAZON"
  },
  "description": "This extension helps to synchronizes Amazon seller api and Amazon Sellercentral",
  "short_name": "CaptainA",
  "homepage_url": "https://captaina.co",
  "icons": {
    "32": "images/icon32.png",
    "48": "images/icon48.png",
    "128": "images/icon128.png"
  },
  "manifest_version": 2,
  "version": "1.4.4",
  "name": "CaptainA.co Helper Extension for AMAZON",
  "optional_permissions": [
    "https://*.amazon.sg/*",
    "https://*.amazon.co.uk/*",
    "https://*.amazon.in/*",
    "https://*.amazon.ca/*",
    "https://*.amazon.de/*",
    "https://*.amazon.co.jp/*",
    "https://*.amazon.fr/*",
    "https://*.amazon.es/*",
    "https://*.amazon.it/*",
    "https://*.amazon.se/*",
    "https://*.amazon.ae/*",
    "https://*.amazon.nl/*",
    "https://*.amazon.com.br/*",
    "https://*.amazon.com.mx/*",
    "https://*.amazon.com.tr/*",
    "https://*.amazon.com.au/*",
    "https://*.amazon.pl/*"
  ],
  "web_accessible_resources": [
    "images/*",
    "js/*",
    "css/*"
  ],
  "permissions": [
    "tabs",
    "webRequest",
    "*://*.captaina.co/*",
    "https://*.amazon.com/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{dea4c2c1-a414-4d88-b9ef-ba5c454ed648}"
    }
  }
}