Does it cost money to use my iPhone apps?

Ok so if I go on my apps like Facebook or angry birds and I don't have Wi-Fi in using 3G will it cost me money like will it go to my bill?

I have an iPhone 4s and I've always used 3G for that kind of thing and it's never charged me for it. I don't know if it depends on your plan/provider or anything but I never get charged. I rarely use Internet on my iPhone always 3G.

Anything going to the internet takes data only… Thats why you have a data plan. Games normally do not go to the net.