WhatsApp APK is a Messenger for smartphone Android and other smartphones. WhatsApp uses to message, voice and video calls with friends and family. Switch from SMS to WhatsApp to send and receive messages, pictures, audio notes, and video messages. WHY USE WHATSAPP. Once you and your friends download the app, you can use it to chat as much as you want. Send a million messages a day to your friends for free. After install user can use it for multimedia send Video, Images, and Voice notes to your friends and contacts. And enjoy group conversations with your contacts.