I got the FitBit for Christmas. I measures your steps, your calories, the calories burned, you can download and track via your phone....I have the tracking software on my laptop. I wear it on my wrist except when charging it...It sends you an email when your unit needs to be charged....just plug into your computer and it charges. When you fill in your food for the day...it is easy...you type a food and immediately a long list of types of that food pop up....or you can input your own calroies info.....it tracks carbs, fat, protein...and it also measures your sleeping hours per day....you just tap the wrist band when you go to bed and tap it again when you get up. It measures the times you are awake during the night and totals your hours of sleep.....what a surprise. It is on target with the sleep and wake times....it charts it for you and at the end of the week, you get a report on all your totals for review. It also tracks your weight loss when you set your weight at the beginning of use...it sets your calories needed per day to maintain your beginning weight, then when your totals fall under that, it is a good thing. Love this unit, still learning about all it can do. I am not an expert, but love what I can track so far.