Phone - this is the tool that can be used today not only as a means of communication. If you have minor children, you can set them spying through the phone to always keep abreast of and at the right time to protect them from the negative effects from these or other contacts.
How often in life it is necessary to know the truth and only the truth. And there can not be any excuses used or even just suspect that you are lying. But not everyone is willing to honestly admit its ji or answer uncomfortable questions, do not lie. Therefore, even just to find out how people honest with you, can help to check on a polygraph.
In every person's life there are very difficult questions to which he did not want to answer. But there are also situations in which these responses are urgently needed. And some of these cases begin just lie and wriggle, trying to convince his interlocutor that he was right.