This week San Francisco-based Fitbit launched two new activity tracking devices: the Fitbit Zip and the Fitbit One, which both connect directly to smartphones via Bluetooth Smart. Legacy Fitbit devices only uploaded information to the Fitbit portal and app when the wearer was nearby a wireless-enabled hub that plugged into the user's computer via USB, and the new Fitbit devices offer this too for users that do not use Bluetooth 4 compatible devices.

Fitbit Zip offers a new smaller form factor that comes in five different colors, a tiny "tap interface" display, and a replaceable watch battery that will last between four to six months before it needs to be replaced. Fitbit Zip is less expensive than other Fitbit devices and retails for $59.95 on the company's website. The Zip device tracks steps taken, distance traveled, and calories burned. The device also comes with a small silicone case that clips onto the user's clothes.

Fitbit One replaces the company's flagship Ultra device, which it launched almost exactly one year ago, and will retail for $99.95. Fitbit One tracks steps, distance, calories burned, stairs climbed, and how well and long the user sleeps. While Ultra brought the new stairs climbed tracking feature last year, the One brings a new alarm function called Silent Wake that will vibrate the device at a scheduled time to only wake up the wearer. The new device also offers a rain and sweat proof casing, a brighter display for reading outside, a clock and the ability to display motivational messages. The device comes in black or burgundy.

Considering it took some two years for the Ultra to replace the company's original Fitbit, the one year iteration shows the company's picking up the pace, especially since this latest launch includes a new less expensive option, too.

Fitbit also announced that it was updating its iPhone and Android apps. Each of the new Fitbit devices will connect to iPhone 4S, the newest iPad, and the soon to launch iPhone 5 via Bluetooth Smart (also known as Bluetooth 5). The devices will synch to these smartphones and tablets automatically without the user having to open up the Fitbit app. Next month the app will also notify users when they are close to achieving set goals and when goals are met.

Another company unveiled a somewhat comparable device and -- certainly similarly named device -- this week: the Fitbug Air. Fitbug, which was founded in 2005, announced its new Bluetooth 4-enabled activity tracker on the same day as Fitbit launched Zip and One. Fitbug Air retails for $29.99 plus $3.99 a month for access to online coaching services. Like Fitbit's Zip, the Fitbug Air uses a tiny battery that will keep the device powered for up to six months. Fitbug Air offers three modes for synching activity data with Bluetooth 4 compatible smartphones and tablets, those include, "Push: to sync on demand at the press of a button; Beacon: to set the Air to automatically syncs at regular intervals throughout the day; and Stream: to let the Air to ‘talk’ to your smartphone in real time, so you can view your progress as you walk." More on Fitbug Air here.

Also of note: At the Apple press conference earlier this month, the company noted that the latest iPod Nano comes preloaded with Nike+ and also has an integrated pedometer. The comments were similar to the ones made last year about the iPod Nano, but showed that Apple continues to push the device as an activity tracker.