Whatsapp a online communicate app.best part this a is it is very easy to used.anybody can used this.but this also also takes time to send message into groups.this is big problem in this app.i request to all if u used this app dont join lots of groups.and dont send to much data in one time.this a is very useful for students .because this app provides give a feature to send a high quality document.whatsapp also provide group call option in new update.and also whatsapp solve crashing problem