By WhatsApp Inc.
A complete app that lets you chat easily with your friends using Wifi or data plan
WhatsApp Messenger is a FREE messaging app available for Android and other smart phones. WhatsApp uses your phone's Internet connection (4G/3G/2G/EDGE or Wi-Fi, as available) to let you message and call friends and family. Switch from SMS to WhatsApp to send and receive messages, calls, photos, videos, documents, and Voice Messages.
The best thing about what makes it so big is its Enormous global user base. It eliminates the need for a texting plan. Encrypted messaging which are secure enables you to have a secure chat or group chat. Group messaging and it’s pro tools enable you to engage with a large number of people easily. Voice calling.