After many rumors, Finally WhatsApp is now available on your desktop. But you will only be able to access if you are Android, Windows phone or BlackBerry user.
New WhatsApp for web is almost similar to WhatsApp on your phone. On desktop, it seems you should have latest version of Google Chrome to use this. You will also need to scan a QR code and have latest version of WhatsApp on your desktop.
WhatsApp founder Jan Koum confirmed that the web version is not available for iOS users because of “Apple platform limitations.”
Source: WhatsApp for Web