SAN FRANCISCO -- Last year, I looked at a neat little device called a Fitbit, designed to encourage you to get off your keister and be more active.
I generally liked it, except for one thing: It could only send its data to a personal computer, an anachronism in this era of the mobile device.
Now there's a new Fitbit -- two versions, actually -- that addresses that weakness. Taking advantage of advances in Bluetooth wireless technology, Fitbit puts data right where it belongs: on the smartphone in your pocket or purse, no PC required.
I've been trying one of the new Fitbits, the $60 Zip, for the last couple of weeks. In general, it worked well and was extremely easy to use, though I ran into significant glitches with the accompanying software.
Wearable activity trackers have proliferated recently. Many of them, such as Nike's FuelBand and BodyMedia's FIT, are considerably more expensive, designed for serious fitness buffs, or both.
Fitbit's goals are much more modest, and its target audience is couch potatoes -- people for whom even a relatively modest amount of extra activity per day can yield significant benefits.
The tiny Zip is half the size of my thumb, weighs about a quarter of an ounce and resembles a Tamagotchi, the digital toy that became a fad in the 1990s.
It comes in five colors, ranging from unobtrusive charcoal to look-at-me magenta, along with a matching rubberlike clip that allows it to be worn on clothing. (My bright lime test unit lived mostly in my pocket.)
The device has a simple monochrome screen. You scroll through its various functions -- primarily steps taken, distance walked and calories burned -- by simply tapping the display. The data is automatically fed to a free Fitbit app on your phone. It's also uploaded to a website, where you can explore it in greater detail.
The original Fitbit was recharged by placing it on a small base station hooked up to a computer. The Zip, by contrast, uses a coin-size battery that should last four to six months before requiring a trip to your neighborhood Radio Shack.
At the moment, Apple's iPhone 4S and iPhone 5 are the only phones with the low-power Bluetooth features needed for direct syncing. You can even set the Fitbit app to automatically update itself in the background, though be careful of the potential battery drain on your phone.
Fitbit says it's working on compatibility for phones running Google's Android operating system. Until then, Android users as well as owners of older iPhones will need the included Bluetooth USB adapter to wirelessly sync with a computer.
The idea behind the Zip is simple: By tracking just how active you've been, or haven't been, you'll want to do more to reach your fitness goals.
Surpassing those goals earns you badges and other digital congratulations. For extra encouragement, you can post your results on Facebook or Twitter. And you can manually enter information on what you've been eating and doing to create a fuller picture of your fitness or lack thereof.
The biggest problems I encountered weren't with the device itself, but with bugs in the app. If I were manually logging an activity, for example, I had to enter "AM" for "PM," and vice versa. Anything I added was automatically assigned to the current day, even if I told the app I had actually done it the day before.
I opened the app once to find all my data missing. After a moment of panic, I completely shut down and relaunched the app, and my information magically reappeared. The company says it recently updated the app to address some problems and is continuing to work on others.
The Fitbit is also limited in what it tracks. If I wanted to get credit for my hour on the stationary bike at the gym -- OK, so it was only 50 minutes -- I had to enter it manually into the app. Ditto for time spent on the exercise machines or doing crunches.
Otherwise, as far as the Fitbit was concerned, I could have been sprawled on the sofa sipping a cold one and watching the San Francisco 49ers. A new model called the Fitbit One, currently available for pre-order for $100, will do more, but only a little: It knows when you're taking the stairs and gives you extra credit for it, measures sleep cycles and has an alarm to wake you when it thinks you will feel most refreshed.
By slipping the PC harness, Fitbit has made an already ultra-easy device even simpler to use. For anyone even moderately concerned about the need to get moving, at $60, it's almost a no-brainer. Or it will be once they clean up that buggy app.