It is instant messaging for smartphones and it is great! It is completely free and a quick and easy way to communicate just like texting. The difference in this than texting is that Kik tells you when a message is sent, delivered, and read. It also tells you when the other person is typing you back just like traditional instant messaging. It is real-time texting. It can be used on several kinds of smartphone devices, so it is not just an Iphone thing. One of my favorite new apps!