Instruct: Classify the given Amazon review into its appropriate rating category
Query: Very cool! A little bit of magic behind the scenes, but still cool

It seems very accurate for weight. You really do need to use the app, which uses some algorithms to give you a lot of the statistics. It uses the stuff it measures, weight and heart beat. Then uses what you tell it, age, height. Then uses an algorithm to give you the rest of the statistics. A little hocus pocus, but seems interesting and fun. All in all, I think it is cool. It's great to track your progress on the app.