Just download, choose your country and you're ready to go.
The on board reverse directory is real nice as you don't have to download a separate application for that.
Just enter a phone number, and it tells you the name and address of the person.
But remember that if the number is unlisted, it will not give out the information.
I think the same is true with most cellular numbers.
The numbers are matched to a Data Base similar to Whitepages.com or it may be that that is the Data Base used. If the number is not in the Data Base, you won't get the info..
Nevertheless, this is some really nice software, especially for the price, FREE