I am using whatsapp from 2 years and really it is the best chatting application ever I used.I also suggested to all my family members to use this application and chat with each other.Whatsapp provides the facilities to communicate like chatting, voice record, photos etc.Anything I want to tell my family members is sent to whatsapp and they read it and reply me about it.
This is 100% legal app.But Now some other types of whatsapp is running in the market like GB whatsapp, whatsapp gold etc.But don't worry I also used this whatsapp and this whatsapp are also legal and giving good service as well as good specification.
If you were not using this application then use it and really it gives you better performance.Regular updates are coming in whatsapp.I will give 4.5 star rating out of five stars.