WhatsApp, the most popular instant messaging app in the world as of now, has its own advantages and disadvantages, of course like any other app.
But compared with many apps like Skype, Viber, Facebook messenger, Gtalk or Hangouts, one of the main disadvantages with WhatsApp has been its lack of computer interface.
It is also due to the fact that WhatsApp relies on phone identification unlike Blackberry which uses a PIN system.
However WhatsApp has addressed this missing feature now officially by providing a web interface which can work on browsers. Particularly with Chrome, it is working nicely.