I am using whatsapp messenger since 3 year now. And I am using his newest version. His concept is simple your all contact connected with you. You can do messaging free worldwide with your contact. Its design and layout is very good. With new version of whatsapp you can also do free calling with your whatsapp contacts worldwide. Features and functions - you can do free messaging with your friends and calling also free of cost. Usefulness - it is very useful for those who wants to be connect with his friends and family.