WhatsApp is the biggest instant messaging service. It is used to make voice calls, video calls, send and receive messages. It was founded by two former Yahoo employs named Jan Koum and Brian Acton in 2008. Whatsapp is actually for Smartphones. But, nowadays, it is being used in Tabls and different smart devices as well. In 2016, Facebook bought this App from its owners in $19 billion US Dollars. Now, Facebook is the parent company of WhatsApp.