Examine source code of Word Counter Pro

{
  "author": "Akash Malik",
  "background": {
    "persistent": false,
    "scripts": [
      "background.js"
    ]
  },
  "description": "It provides wordcount for every single click for a specific page",
  "icons": {
    "16": "icon-16.png",
    "48": "icon-48.png",
    "128": "icon-128.png"
  },
  "key": "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAnuq57aYk7GmyZ9xImOALb9aJe2QMoNHhXOP9mgWNjiRhuXxhFAhPXLthzQBanXunrJ0SaTPlt0OzPr4dsu42PTS2Q1UFaQE/gPDdZbme1yk+v1qLQ4aLWR27DRBbOxeiDexMLgi1PMAorQD4OdwrFywfdAwdU/vYwg5R34TQKwQ/jLpQCGTmoqoHJoJecfDe8JcOU0+y88Tx2Td4qMG1FmsTJCjtR26KH/gtR2hsneBUSQKW9yncS9PjKv5Caa7jIRlfyoLQlvizt2EU1i5irsf9ootCU/6QPPEoepPNDrdFfU1j2MmOWyXMosZBbTCe6s0jTY8OnJk5OldEnYPbbwIDAQAB",
  "manifest_version": 2,
  "minimum_chrome_version": "41.0",
  "name": "Word Counter Pro",
  "offline_enabled": true,
  "permissions": [
    "contextMenus"
  ],
  "update_url": "https://clients2.google.com/service/update2/crx",
  "version": "1.0"
}