I bought a Fitbit last June. It's a tracking device which is designed to help you to keep the control of your weight, measure your sleep amount and see how active you are daily and weekly. While it seems to be helpful, it won't work until you feed it accurate, continuous data on daily basis. The less data you provide, the less result you get and it become almost useless.
The other problem with it is it runs out of the battery very soon and then becomes a pain in the butt. You have to recharge the battery at least every two days depending on how you get it to work for you. It also works as a silent alarm which is very good for couples who don't have to wake up at the same time in the morning. It vibrates on your wrist and wakes you up. However you can attach it to your ankle too but don't think it's a good idea.
The main problem with Fitbit similar to may other products in North America is lack of support. If you run into a problem there is really no place or no person that you can go to and complain unless you contact them which does not seem to be very helpful. Companies these days don't even print a manual anymore. They either refer you to their website or give you a CD with a big PDF file. These guys have done none! I guess the only way to discuss your issues with them would be e-mailing, which I haven't tried or going to the forums. Forum helped me once with a small question I had. People all were helpful and friendly but where is the damn company? Nowhere to be found. So finally does it worth the $100 you pay for it. I can't say for sure. I guess these days Smart Phones provide the same service. Smart Phones these days do everything for you although I wouldn't know much as I have never had one and will never spend money on them but if you're planning to by a Fitbit make sure that your Smart Phone does not provide the same service as it would then be a waste of money. I know for sure that you can synchronize your Fitbit and get the displays on a Smart Phone, something that I do on my PC. So do a little research first. I will post a secondary review later on after I get it to work more for me.
(Photo: A Fitbit Flex comes in a box and has two wristband with two different sizes)