Alongside Apple's iOS 15.4 update for the iPhone, which brought new emoji, anti-stalking features for AirTags and a gender-neutral Siri voice (plus a fix for a battery drain issue in the subsequent iOS 15.4.1 release), the company also released a software update for its Apple Watch. The software, which wasn't highlighted during the company's "Peek Performance" event in March, is primarily focused on Apple TV, Apple Fitness Plus, heart rhythm detection and digital COVID-19 vaccination cards.

Called WatchOS 8.5, the software is the fifth major update Apple has provided for free to Apple Watch owners since releasing WatchOS 8 last fall. 

When was the WatchOS 8.5 release date?

WatchOS 8.5 was released on Monday, March 14, alongside iOS 15.4 and iPadOS 15.4.

How do I download WatchOS 8.5?

You must download iOS 15.4 onto your phone before you can upgrade your Apple Watch. You can download iOS 15.4 by going to Settings > General > Software Update > Download and Install. Once that's finished, the software will restart your phone. Then you can go to the Watch App > General > Software Update. Apple Watch updates are typically scheduled for the evening, when people tend to take them off for charging.

Heart rhythm detection improvements

One of the most popular features of the Apple Watch is its health monitoring capabilities. There are many stories of the Apple Watch identifying and alerting people to heart problems before they feel symptoms. Apple said with WatchOS 8.5, it improved software to detect atrial fibrillation, the most common type of irregular heartbeat, which can indicate major risks for stroke. The new detection software is available in the US, Chile, Hong Kong, South Africa and, Apple says, "many more regions where the feature is available."

More Apple TV 

Another popular feature of the Apple Watch is its ability to serve as a password device, authorizing sign-ins for apps like Microsoft's Authenticator and the business login software Okta. Now, Apple says, WatchOS 8.5 users will be able to authorize purchases of TV episodes and movies through its Apple TV iTunes Store service.

Better Apple Fitness Plus 

Apple's also bulking up its $10-per-month Apple Fitness Plus service with new features for users with disabilities. It's already added health features to the Apple Watch like wheelchair workout detection. Now Apple Fitness Plus will have optional audio commentary describing visually demonstrated moves in a workout.

COVID-19 vaccination cards in Europe

One tool that's helped the world slowly adjust to life in the pandemic has been vaccine cards, which allow businesses to identify people who've been vaccinated against COVID-19 when entering an establishment. Over the past year, tech companies have gotten involved, offering easy ways to add COVID health records to our phones. The Apple Watch will now support a new format, called the EU Digital COVID Certificate, which has become an important part of travel in Europe.