The WhatsApp Android application works with your mobile number and users your mobile address book to add the friend list. The WhatsApp application has been Always On and Connected mobile messenger. You no need to add the contact manually. Your contacts already installed WhatsApp messenger will be displayed in your friends list automatically. This application also supports offline messaging service. The WhatsApp offer several incredible services such as exchange contacts, share location, custom notification sound, custom wallpaper, landscape mode, message time stamps, email chat history, MMS, broadcast messages and much more.