Disclaimer: this skill is a prank skill for entertainment purposes only and does not actually tell you whether anything is true or false.
Is It True? lets you ask any True/False question and get an answer! You control the answer in the way you phrase your question.
If you ask a question in the form "Is it true that...?", the skill will respond saying that it is true. If, however, you ask a question in the form "Is it really true that...?", the skill will respond saying it is false. Other natural phrasings can work, but the presence of the word "really" will always be what makes the answer no instead of yes.
For your friends (or your children) who don't know the trick, this will seem like independent confirmation of your opinion.