What it is
You call your friends and relatives. You can opt to use video calls or not. It is an Apple exclusive app.
Pros
You can call other people and send information.
It is quick and easy.
Good quality video calls.
You can hide your camera if you want to.
Cons
People can see your face
Other people can record it, if they have the right tools
How to stay safe
Do not send personal information
Hide your camera if you do not know the person.
Do not answer calls from strangers.