The way to use this internet phone service is by calling one of the so called gateway numbers placed throughout the States. If one lives outside toll free zone for that number then there is naturally a charge for calling it from the local phone company - unless one has a domestic or cell phone plan that covers that. Otherwise, say if one lives in the same city where the gateway number corresponds to it then the call to it is automatically free.
 
For mobile phone users additional fees from their cell phone providers might apply. On unlimited minutes the call should be free although one needs to be careful not to press the 'send' or 'call' button or retrieve the number from the cell phone’s directory - after calling the gateway number - otherwise one can be billed the high rates by the given mobile phone provider.

On December 6th, this year - there is also to be released a list of additional 40 or so countries to which unlimited VoIP calling can be done for a flat fee of $10 per month, paid monthly.

Some other details include being able to call only from a pre-specified by user IP or phone number as well as $0.25 per minute charge to most countries not listed in the free call plan and $0.75 per minute to special access countries - when subscribed to their Free Call Planet Plus plan.

According to the company the free call plan has no termination point at this time although it is a part of their promotion program and can be withdrawn at any time.

A unique and nice feature of the Free Call Planet service is that it allows originating the calls through regular PSTN (Public Switched Telephone Network) service. In other words you can make the VoIP call by using regular phone - no computer or IP phone is needed.