Apple released WatchOS 9.4聽on Monday, bringing cycle tracking and atrial fibrillation features to more聽Apple Watch聽users, and fixed a minor alarm bug.

The update is coming to models Series 4 or later, SE and Ultra, bringing AFib History, which detects atrial fibrillation (irregular heart beats), to more countries, specifically Colombia, Malaysia, Moldova, Thailand and Ukraine. Cycle Tracking, which tracks menstrual cycles, is also being expanded to Moldova and Ukraine.

Wake-up alarms on the Watch can no longer be silenced with the "cover-to-mute" gesture, which Apple says will help avoid accidental alarm cancellations while sleeping.

Apple also released iOS 16.4 for iPhone on Monday, bringing new emoji and better call quality.

Monday's update is the fourth major one to come to WatchOS 9. Launched in September, it brought visual improvements to better mimic the iPhone experience. It also gave people new ways to track their sleep with Sleep Stages, brought a low-power mode to extend battery life聽and gave improved telemetry for runners. 聽

Apple's continued development of WatchOS has helped the Apple Watch line dominate the smartwatch market. Given how intimate the Apple Watch is to users, analysts say it's the stickiest product in Apple's ecosystem, making it difficult for users to switch to other platforms like Fitbit or Android's Wear OS.