WhatsApp is one of the most popular cross-platform smartphone messenger currently available for iPhone, Android, Blackberry and other smartphones. WhatsApp allow users to send free text messenger among friends who also have WhatsApp installed as long as you gain internet access. Within your text message, you can also put in audio notes, video messages & pictures. I am quite amazed with the speed of WhatsApp in sending text message as compared to other free text messengers since I have tried quite a number of these applications before. For now, you can download WhatsApp for iOS in iTunes for absolutely free in a limited time.