WhatsApp is probably one of the best messaging apps developed for iOS & Android. In 2014, the media went nuts after Facebook completed the deal of buying WhatsApp for astonishing $19 billion dollars. WhatApp is one of most popular messaging apps that enables you to send videos, pictures, text messages or even call your friend with WiFi connection. WhatApp works free and without adverts. Setting up is very simple. You download it and once the app is installed on your system you will be required to enter your phone number for verification of the user, it needs your phone number because it works in similar way as SMS system, routing messages and other data between you and other contacts.