Both devices sport Bluetooth 4.0 compatibility, expanding the wireless syncing features of the current Fitbit Ultra. Bluetooth 4.0 offers very low-energy usage and easy pairing, which makes it ideal for health and fitness accessories. The advanced Bluetooth support means users will be able to sync with compatible devices such as the iPhone 4S and iPhone 5 and the third generation iPad to track their progress. And coming in October, users will be able to get real-time notifications as they approach or complete daily goals or pass friends on a new daily leaderboard system.

Previously, Fitbit Ultra synced only when it came close to a wireless base station that connected to a computer. Fitbit’s iOS and Android apps were only able to show a snapshot of the data from the most recent sync. Now, the mobile apps will be a lot more useful to users, helping them see their current progress more easily and also them to engage with Fitbit’s new social features, which includes messaging with friends.

The Fitbit One will replace the Ultra, which is being phased out. Like the Ultra, the One will not just measure daily steps, distance and calories burned, but it also serves as a sleep monitor, tracking sleep time and the number of times a user wakes up. And the One will also feature a new vibrating alarm so users can wake up without having to disturb their partner. The One, available in Black and Burgundy, is also 40 percent of the size of the Ultra and will sport a clock and provide motivating messages. It will sell later this fall for $99.95, the same price as the Ultra.

The Fitbit Zip is even smaller than the One at about the size of a quarter and will focus solely on activity tracking. It will be sold in five colors and will also come with a Bluetooth 4.0 microdongle, which can be inserted into any computer for wireless syncing. At $59.95, the Fitbit Zip will allow the company to widen its appeal to more cost-conscious consumers. The Fitbit Zip is available now while the Fitbit One can be pre-ordered.

Fitbit, which is now sold in 7,000 locations in the U.S., is facing more competition from the Nike+ Fuel Band and Striiv gamified pedometer. But CEO James Park believes the company can stay ahead by smartly leveraging technology innovations like Bluetooth 4.0 to make Fitbit trackers even more useful and seamless for users.

“With wearable health devices, you just want the devices and sensors to disappear into your lifestyle. That’s the big thing,” he said.

Disclosure: Fitbit is backed by True Ventures, a venture capital firm that is an investor in the parent company of this blog, Giga Omni Media. Om Malik, founder of Giga Omni Media, is also a venture partner at True.

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