It's a
Truth Detector, Decoder and International Timepiece in One! Just ask a person a question as they hold two fingers against the watch's bio-feedback sensors.
"The more bars appear on the screen, the less likely it is they are being honest. Look for other clues, such as rapid eye movement or a flushed face to help you decide." The one customer comment at the bottom of the screen says that it's "Better than expected." Not exactly a ringing endorsement, but I still can't imagine that the thing would be anything but useless at actually spotting lies.
Comments
*"In a 1983 Federal study of polygraph accuracy, the author of the study, Leonard Saxe, stated the following about the polygraph, "It doesn't work. It's not accurate, and can lead to what are called false positives, finding people untruthful when in fact they are truthful, and the opposite.""