I use the Fitbit One and love that and the Fitbit app for iPhone. I have passed the Fitbit Aria Wi-Fi Smart Scale a number of times over the past couple of years at Best Buy, at other retailers and online. It sells for $129.99 which I think is way to pricey. But recently, I noticed that it is on sale just about everywhere for $30 off! Still, $99.99 is still quite pricey as far as I'm concerned, but I decided to bite the bullet.
Oh, and let me add that this is the newly released model that I bought and that is currently (as of this writing) still on sale. It is now the Fitbit - Aria 2 Wi-Fi Smart Scale.
The scale keeps me more honest than a regular scale. This one "tattles" on you (well it sends my weight, fat percentage, and BMI right to MY Fitbit app--I should make clear that when I say "tattles" it doesn't share that info with others...unless you perhaps set up to share your data with a spouse or a friend etc., and I don't know if you can opt what information to share. For instance only steps? Water intake? Weight? etc. I don't know if sharing your Fitbit app data is an all or nothing proposition).
I believe a lot of people use the sharing the Fitbit app data for friendly competitions between friends and so forth. I tried it once with one friend and didn't like it. I did always have more steps than he did, but I didn't like the feeling it gave me. The only reference point I need is to compete against myself and know where I am (number of steps, weight, etc) and track my progress (or see where I am being lazy) as I go along.
With a regular bathroom scale, it is easy to forget or fudge the numbers in your mind (and not many of us take the time to make a written weight log).
I'm so glad they at least temporarily dropped the price $30 because I really like the scale.
Another thing. Let's say you usually weigh your self at the same time in the morning after waking up and before drinking any fluids or water, and being naked on the scale (I've always heard this is the most accurate way to compare weight fluctuation.
So let's say one day you decide to get on the scale after lunch. It will send your weight, percentage of body weight and BMI to your app. But, you can easily tap and remove that weigh-in from the app so it doesn't count "against" you.
Another neat thing is that the app automatically calculates your average for the week (and actually calculates the new average--for the week daily--each time you weigh yourself). For example, If you weigh your self Sunday, Monday, and Tuesday, it will give you the average for the week after each weigh-in, and will continue to do that until the end of the week, and then it starts the average week calculations over, but you always retain previous week's averages.