Examine source code of ASIN Collector

{
  "manifest_version": 2,
  "name": "ASIN Collector",
  "short_name": "asincollector",
  "description": "This extension use to collect amazon asin",
  "version": "1.0",
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "browser_action": {
    "default_icon": "icon48.png",
    "default_popup": "popup.html",
    "default_title": "ASIN Collector"
  },
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "permissions": [
    "activeTab",
    "*://*.amazon.com/*",
    "*://*.amazon.co.uk/*",
    "*://*.amazon.de/*",
    "*://*.amazon.cn/*",
    "*://*.amazon.it/*",
    "*://*.amazon.es/*",
    "*://*.amazon.co.jp/*",
    "*://*.amazon.ca/*",
    "*://*.amazon.fr/*",
    "*://*.amazon.in/*",
    "*://*.amazon.com.mx/*",
    "*://*.amazon.com.br/*"
  ],
  "web_accessible_resources": [
    "client/*",
    "js/*"
  ]
}