I can't find Facetime app on my iPhone 4s?

I could see it on my iPad but not on my phone.

Call a phone number and there should be the option to FaceTime while its calling

The iPhone 4S does not have a FaceTime icon unlike an iPad does. To facetime with someone, go to your Contacts, find the person you want to FaceTime, edit the contact and set the FaceTime info (email or number), then save and tap "Factime" Home or Email.

There's no actual FaceTime app on the iPhone. It's integrated to the phone app.

New user eh