Examine source code of Email Verifier

{
  "manifest_version": 2,
  "name": "Email Verifier",
  "short_name": "Email Verifier",
  "description": "The Email Verifier does a complete check of the email address to let you send your emails with a complete confidence.",
  "version": "2.1",
  "permissions": [
    "storage",
    "tabs",
    "http://*/",
    "http://*/*",
    "https://*/*",
    "notifications",
    "downloads"
  ],
  "icons": {
    "16": "images/icon16.png",
    "32": "images/icon32.png",
    "48": "images/icon48.png",
    "128": "images/icon128.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "images/icon16.png",
      "32": "images/icon32.png",
      "48": "images/icon48.png",
      "128": "images/icon128.png"
    },
    "default_title": "Email Verifier",
    "default_popup": "popup.html"
  }
}