VoipBuster is a completely free tool you can use to communicate with relatives, your friends, employees and coworkers all over the world and without paying a single penny. This application works as an instant messenger but better. All you have to do is to install it in your computer and tell your friends and family to install it too. You will be able to connect and talk to them via P2P totally free.
It has a colorful and cool interface you will find very fun to use. In addition to that this application is really light so it won't consume any of your system resources while you are running it and working.