by WhatsApp Inc.
Download this app if: you want to make the switch from SMS.
WhatsApp Messenger is a FREE messaging app available for Android and other smartphones. 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,...
WTF is Up with Whatsapp? — I downloaded this to my Galaxy Nexus with all my hundreds of contacts visible but it only shows I have 15 contacts that use the app and I know there are more. I even manually entered a new contact overseas, refreshed and it still does not come up in my contact list.