KATZ is a communicator that allows you to make text and voice calls for free, as well as calls to landline and mobile numbers for a fee (KATZ Out service). In order to use the communicator, you first need to run its equivalent on your smartphone and enter the phone number. The application then reads the contacts from the address book and finds the numbers of users using KATZ, which will also appear on the computer.

After that, you can call your friends or send them messages without hindrance. In the program settings you can choose what notifications will be displayed and where on the screen, what devices will be used during calls and whether it will be started together with the system. You can also top up your KATZ Out account here.