Enter WhatsApp, a text messaging app for iPhone, Android, BlackBerry, and Nokia phones that allows you to message contacts on any device, completely free of charge. Well, free of charge after paying the $1 to download the app, which will pay for itself in approximately one conversation. Even Savvy approves! Learn more about WhatsApp after the jump.
Besides text messaging, WhatsApp users can also send unlimited photo, video, and voice messages to each other. Enable push notifications to receive immediate alerts when you receive a text, and even set a status message to let your friends and contacts know whether you are able to send or receive messages.