No but my neighbor has one and she swears by it. It kept track of her exercise, and she also used an app called My Fitness Pal, (I think that’s what it’s called). She lost a bunch of weight because of her diligent adherence to the Fitbit and the app.
I was excited to get one for Christmas last year, but I haven’t used it yet. The model I received doesn’t work with XP, which my 2 PCs and laptop are running. No smart phones or other portable devices in the household.