I am using WhatsApp from last 3 years. As everyone has smartphone and they all have WhatsApp installed in it. Now I am sharing the benefits of WhatsApp : -
This is very secure.
Your chat or data will be within 2 persons with whom you share it.
Its is very good that you can share images, music, video, links and many more type of data .
Now, WhatsApp has updated one more feature that you can delete sent message within 10minutes after seen also.
Video call is also available.
Audio is very good in condition that you cant talk by your number.
Concept of WhatsApp is superb. Features are awesome as you can put written or image status. It is designed perfectly. It is very useful in today life.