Can an app make phone calls in the background I saw a number of apps that require "Services that cost you money" permissions, my question is if I install such an app and that app will make a phone call, is that call visible to the user or the app can make the call in the background without the user knowing ?

I usually don't install apps that require extending permissions and I haven’t found anything googling, I prefer not to install it unless I'm sure I won't have a surprise when my phone bill comes.

Specifically I was invited to join a conference via GoToMeeting and their Android app is requesting the above permission.
I am an Android Application developer. I had a requirement to make phone verification. In that case we had to make a telephony call to our server. But we could't achieve that as Android system does not allow us to make a phone call without users interaction. The best we can do is populate the phone number in the default dialer app. In any case user has to press call button. So I would say No app can make a phone call without your permission. 

But

We can send SMS in from background and it will cost you money. For this you will see something like this before installing app: