This is an amazing invention, really thanks to that person who invented this, as we make too many groups, we can share pictures, quotes, messages, emoticons in it.it is the quickest method to reach a person now a days if you are finding it difficult to talk to a particular person.
You can keep your display picture, keep your own status too, it has very expressive emoticons to show how you feel at that moment.
You can also check that person was available at what time? if is he online? if the message has been sent, delivered and read by that person or not?
Good feature is it has privacy too maintain, you can keep your all gropus on mute from constant buzzing.