Examine source code of ExtStore - Amazon Reviews Exporter

{
  "manifest_version" : 3 ,
  "name" : "__MSG_extName__" ,
  "description" : "__MSG_extDesc__" ,
  "version" : "1.1.4",
  "icons" : {
    "16" : "icons/16.png",
    "32" : "icons/32.png",
    "48" : "icons/48.png",
    "128" : "icons/128.png"
  },
  "default_locale" : "en" ,
  "action" : {},
  "permissions" : [
    "storage" 
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "amazon-data-exporter@extstore.dev",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "host_permissions" : [
    "*://*.extstore.dev/*" ,
    "*://*.amazon.com.au/*" ,
    "*://*.amazon.com.be/*" ,
    "*://*.amazon.com.br/*" ,
    "*://*.amazon.ca/*" ,
    "*://*.amazon.cn/*" ,
    "*://*.amazon.eg/*" ,
    "*://*.amazon.fr/*" ,
    "*://*.amazon.de/*" ,
    "*://*.amazon.in/*" ,
    "*://*.amazon.it/*" ,
    "*://*.amazon.co.jp/*" ,
    "*://*.amazon.com.mx/*" ,
    "*://*.amazon.nl/*" ,
    "*://*.amazon.pl/*" ,
    "*://*.amazon.sa/*" ,
    "*://*.amazon.sg/*" ,
    "*://*.amazon.co.za/*" ,
    "*://*.amazon.es/*" ,
    "*://*.amazon.se/*" ,
    "*://*.amazon.com.tr/*" ,
    "*://*.amazon.ae/*" ,
    "*://*.amazon.co.uk/*" ,
    "*://*.amazon.com/*" 
  ],
  "background" : {
    "scripts" : [
      "background.js" 
    ]
  },
  "options_ui" : {
    "open_in_tab": true,
    "page": "options.html" 
  },
  "content_scripts" : [
    {
      "matches" : [
        "*://*.amazon.ae/*" ,
        "*://*.amazon.ca/*" ,
        "*://*.amazon.cn/*" ,
        "*://*.amazon.co.jp/*" ,
        "*://*.amazon.co.uk/*" ,
        "*://*.amazon.co.za/*" ,
        "*://*.amazon.com.au/*" ,
        "*://*.amazon.com.be/*" ,
        "*://*.amazon.com.br/*" ,
        "*://*.amazon.com.mx/*" ,
        "*://*.amazon.com.tr/*" ,
        "*://*.amazon.com/*" ,
        "*://*.amazon.de/*" ,
        "*://*.amazon.eg/*" ,
        "*://*.amazon.es/*" ,
        "*://*.amazon.fr/*" ,
        "*://*.amazon.in/*" ,
        "*://*.amazon.it/*" ,
        "*://*.amazon.nl/*" ,
        "*://*.amazon.pl/*" ,
        "*://*.amazon.sa/*" ,
        "*://*.amazon.se/*" ,
        "*://*.amazon.sg/*" 
      ],
      "all_frames" : true ,
      "css" : [
        "content-scripts/amazon.css" 
      ],
      "js" : [
        "content-scripts/amazon.js" 
      ]
    },
    {
      "matches" : [
        "*://*.extstore.dev/*" 
      ],
      "run_at" : "document_start" ,
      "js" : [
        "content-scripts/extstore.js" 
      ]
    },
    {
      "matches" : [
        "*://*.extstore.dev/*" ,
        "http://localhost:3000/*" 
      ],
      "run_at" : "document_start" ,
      "js" : [
        "content-scripts/main.js" 
      ],
      "world" : "MAIN" 
    }
  ]
}