How to get FaceTime on iPhone 5?

I have the iPhone 5, and I want to talk to my friends on FaceTime but I don't know how to get it on there or what is the best app please help?!

This one is a little odd i'm not sure if it did but i think my dad's came with it already on there and the same thing with my IPod touch but just goto the app store and search "FaceTime" hope this helped.

You go in settings and activate it you facetime on the persons contact page. And the ipods and ipads come with the app, app not available on iphones

Its already on it. Just go to a contact that has a FT enabled device as well through the Contacts app, press the FaceTime button & you will start a FT call.