Fitbit gave Apple a two-and-a-half-year head start on smartwatches. Now it's finally trying to catch up.

The leader in wearable devices is hoping the Fitbit Ionic will drum up interest in its brand and a tech category that's lost some appeal.

The "space-themed" smartwatch ($299.95) is $30 more than the starting price for the Apple Watch, its biggest competitor. That's a hefty price to ask of people who may already own a smartwatch or are cautious about investing in one for the first time.

The Ionic has everything you'd expect from a fitness device: sleep and activity tracking, a heart rate monitor, GPS integration, smart notifications and long battery life -- one of its biggest selling points. It'll last up to four days, compared with 18 hours for the Apple Watch.

The waterproof Ionic comes sprinkled with additions for fitness fanatics, too. There's a sensor that measures oxygen in the blood and personalized workouts that adapt to your feedback.

You can work toward goals -- such as running a mile faster -- listen to audio coaching and store up to 300 songs on the device. The Ionic also features a payments system called Fitbit Pay that allows you to tap the device at checkout to pay.

The Ionic is Fitbit's first product with both hardware and software, Fitbit OS, designed in house. Jonah Becker, vice president of design, said the device was inspired by the concept of a "space journey" and "progressive thinking that gets you to a destination."

"The space theme influences the color palate," said Becker, referencing the orange, blue and steel color options. "Think about 'The Martian' ... think about Elon Musk colonizing Mars ... and the icy landscape of 'Interstellar.'"

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The Ionic features a lightweight casing made of aluminum and a colored spherical glass touch screen.

The company flirted with a smartwatch before with the Fitbit Blaze. But CEO James Park previously said the category didn't make sense for the company -- that smartwatches lacked "purpose." Now it's changed its mind.

"We're not entering the category for the sake of entering the category," Park told a group of reporters in New York City last week. "For us, there's a purpose. We feel very strongly that smartwatches are a platform for us to deliver the most powerful tools the market has seen. The larger form factor of smartwatches versus activity and fitness trackers allow us to integrate many more advanced sensors and provide richer displays and user interfaces."

But Fitbit (FIT) has catching up to do. Smartwatches are a $10 billion market, and that's expected to double in four years, according to IDC. But shipments of wearables were also down late last year compared with the year before.

Experts believe the category will surge again once smartwatches are freed from the smartphone. The Ionic, like the Apple Watch, requires a sync from a smartphone, but Fitbit plans to launch a version next year that won't. And the pay feature already means you can leave your wallet at home.

The Ionic also comes with apps from Starbucks (SBUX) and AccuWeather and music streaming from Pandora. Other developers can start building apps for the Ionic starting in September.

Apple (AAPL) is expected to launch a cellular version next month.

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Apple also recently reported its best quarter yet for wearables. Fitbit's stock has plunged 60% in the past year and now trades 70% below the IPO price. Yet it still holds the No. 1 spot for health app downloads on iTunes and Android.

In addition to the Ionic smartwatch, the company revealed its first Bluetooth wireless earbuds and a second version of the popular Aria smart scale. It also promoted future Ionic features, including sleep apnea tracking, and its vision for disease screening and monitoring for research.

Fitbit is emphasizing fashion, too. As with the Fitbit Charge and Alta, you can swap out bands and upgrade to premium options like leather ($29.95 each). Fashion brands like Fossil, and its sub-brands like Kate Spade, Emporio Armani and Michael Kors -- have added smart features to accessories.

Fitbit is clearly late to the smartwatch race, and it's unclear whether the Ionic will be enough to fix that. But Park said he's confident Fitbit is the "best positioned company to have the most profound impact on people's health outside of the healthcare system."

This story was updated from its original version to clarify the starting price of the Apple Watch.