WhatsApp

WhatsApp Messenger is a freeware and cross-platform messaging and voice over IP (VoIP) service owned by Meta. The application allows the sending of text messages and voice calls, as well as video calls, images and other media, documents, and user location. 
The application runs from a mobile device though it is also accessible from desktop computers. The service requires consumer users to provide a standard cellular mobile number. Originally users could only communicate with other users individually or in groups of individual users. In September 2017 WhatsApp announced a forthcoming business platform which will enable companies to provide customer service to users.