Is the StarCall app like face time with kpop idols? And how do you use it?

Is StarCall supposed to be like face time on the iPhone?
I've been looking at video's of other people's Star Call and it looks pre recorded. I don't know:/
How can you call kpop idols? I saw in the Super Junior StarCall video that it gave a number. Do I call it and then I video-chat with them? Or do I just wait for them to call me?

They're pre-recorded.
After a while when I didn't pick up the phone when an idol called, StarCall began asking to charge when I tried to watch the missed video.
I deleted the app in the end: P
I was really hoping it would be a "fan to idol conversation", but it's a "idol records self then distributes to all users" ---;

It's precorded video.

The star sends it right after recording it. So when you pick up when the app notifies you, it will look like as if you were recieving a call from the star. You can also send video messages (fan mail) to them.

But in short, StarCall isn't exactly like FaceTime.

Starcall is like YouTube. The idols record the video and send it to their followers. However you can video call them. They will not see your face live and neither will you see their face live (at the same time).

When you video call them they will join a long list of other video calls for them to see.
So they will see you, it's just your not going to do a conversation with them like one on one.

However I wish it was like that.