Apple has been the top seller of wearable computing devices for the past few years, thanks to the popularity of its smartwatches and AirPod wireless earbuds. But with competitors like Fitbit, Samsung, and Garmin adding new features to their competing devices, Apple can’t afford to stand still.

The fifth generation update of the Apple Watch isn’t expected until the fall, but this week Apple holds its annual World Wide Developer Conference, known as WWDC, where it will debut the sixth generation of the software that runs on the watch. And, as it has done for the past few years, Apple will offer users some enticing new features, especially around health and wellness, analysts say.

“Health and fitness has to be the primary focus for the smart watch,” says Ramon Llamas, research director for mobile devices at IDC. “It’s the one feature that people can wrap their brains around and use on a regular basis.”

Last year, Apple added an ECG measuring feature and fall detection. According to leaks, this year will see the addition of an Apple app to help users organize and remember when to take their medications and another that will help women track their menstrual cycles. Third party developers have offered similar apps, but Apple will build in the capabilities for all users. Apple could also leverage the heart rate studies it has participated in by adding further hearth health detection features, Llamas says.

Some more significant new health features in development, like measuring blood pressure or glucose levels for diabetes patients, aren’t ready yet for 2019 but could be coming in a few more years, analysts say.

Another recent priority at Apple aapl has been helping customers be less addicted to their smartphones. Adding more well-thought-out apps to the watch as a replacement for using the iPhone could further the “screen detox” effort, Creative Strategies analyst Carolina Milanesi says. “I have been using it as such since it came out, but it could be doing so much more if apps were developed with that in mind,” she says.

Apple itself doesn’t disclose sales of its wearable devices, but the company captured 27% of the wearable market last year, according to estimates from IDC. The category now goes beyond smartwatches and fitness trackers to include earpods and headphones that connect to digital assistants. Chinese gadget maker Xiaomi ranked second at 14%, and Fitbit, which once dominated the category, slipped to third place with 8%. Huawei and Samsung closed out the top five, as some top 2017 manufacturers, like Garmin grmn and Fossil fosl , which aren’t big in the headphone space, got pushed out of the rankings.

Still, the competition has been trying to match or exceed the Apple Watch’s capabilities, keeping the pressure on Apple.

Garmin’s vivoactive 3 Music smartwatch, which can connect to wireless networks on its own (without a linked smartphone), went on sale at the end of March, matching the cellular feature that Apple added two years ago. Garmin has also introduced a high-end line of luxury smartwatches starting at $1,500 under the MARQ brand name, designed perhaps to steal some of Apple’s more status-hungry watch wearers.

Fitbit has focused on beating some of Apple’s health and fitness features while offering much lower prices. The company’s Versa Lite watch costs just $160 versus $400 for the cheapest of Apple’s Series 4 watches. Fitbit fit also introduced a period and birth control tracking app a year ago and claims 10 million users have already tried it. It’s also long offered in-depth sleep tracking, a feature that’s only available on the Apple Watch via third party apps that aren’t as seamless.

Apple remains well ahead of the competition in terms of the total number of available watch apps. The sixth version of Apple watch software is rumored to be taking a further step to encourage developers to keep Apple’s platform foremost in mind, with a separate app store right on the watch. Currently, Apple watch users, as well as users of rival devices, generally select and manage watch apps on their phones. The new Apple watch on-wrist app store could encourage developers to be more creative and makes the watch less dependent on a user’s phone, but the usability may be a concern, says IDC’s Llamas.

“I like this as a way to move the watch away from the iPhone and make it a more standalone device,” he says. “However, the practicality of discovering apps on a watch can be challenging.”