After verification via SMS, you can start using the app. In order to use WhatsApp Messenger, a phone number is required. When you grant WhatsApp Messenger access to your contacts, the app will show you all the contacts that have it installed, and you will be able to talk to them, whether they are iOS, Windows or Android users. As the most widely used messaging app in the world, by installing it there is a high probability of finding the person you want to talk to. To talk to a person through WhatsApp, the other person needs to have the app installed. WhatsApp Messenger was the first major instant messaging application for Android, and that has earned it a place at the top.
It has more than 2 billion active users, who send more than 100 billion messages daily. WhatsApp Messenger is the most widely used instant messaging application in the world.
