Examine source code of Netmap VPN - Free Proxy

{
  "manifest_version" : 2 ,
  "name" : "Netmap VPN - Free Proxy",
  "version" : "1.0.6",
  "description" : "Set proxy for Firefox Platform",
  "author": "Netmap",
  "icons" : {
    "128" : "icons/disconnected.png"
  },
  "browser_action" : {
    "default_title" : "Use this to open the popup",
    "default_popup" : "popup/popup.html"
  },
  "background" : {
    "scripts" : [
      "background.js" 
    ]
  },
  "permissions" : [
    "tabs" ,
    "proxy" ,
    "<all_urls>" ,
    "webRequest" ,
    "webRequestBlocking" 
  ]
}