And if you haven't just shelled out for Apple's best smartwatches, there's also good news: many of the features are coming to your Apple Watch too. If your Watch is compatible with iOS 9, there are some cool new features incoming.
Here's what to expect, starting with model-specific features.
1. 60 hours of battery life (Apple Watch Ultra)
Apple will launch its special low power mode for the Apple Watch Ultra "this fall", and promises a whopping 60 hours of battery life by cutting down the frequency of GPS and heart rate updates. According to Apple, you'll be able to log 15 hours of workouts, check the time 600 times, use apps for 35 minutes, talk in calls for 3 minutes and track your sleep for 15 hours before your Apple Watch Ultra will need to recharge.
2. Depth tracking for deep dives (Apple Watch Ultra)
It's not there yet, but the Oceanic+ app will turn your Apple Watch Ultra into a diving computer for free. It'll give you depth tracking and depth alarms, GPS tracking, snorkelling and logging of up to 12 dives in the free version. There's also a paid-for version ($4.99/day to $79 a year) to add more advanced options such as decompression limits.
3. International roaming (Cellular models)
If you have the cellular version of the Apple Watch Series 5 or later, you'll be able to use your data plan globally. Apple has signed deals with 30 carriers internationally including Three and O2 in the UK and Verizon, AT&T and T-Mobile in the US. There's no launch date for this feature yet but Apple says it'll go live before the end of the calendar year.
4. Race Route (all models)
Race Route is coming to every Apple Watch from the Series 4 onwards, enabling you to track your results on frequently completed routes and giving you pacing guidance to help you achieve your personal bests. This one is coming to the Workout app later this year.
5. Track running (all models)
Another feature coming to every Apple Watch from the Series 4 onwards is automatic track detection, which can identify when you arrive at a running track and give you GPS data down to specific running lanes. Initially this feature will only work for US locations but it should roll out to more places next year.
6. Home support for kids (all models)
One of the best features for parents, Family Setup, will soon enable you to give the kids control of selected Home devices such as your HomePods mini and other smart home kit. You'll also be able to store digital keys such as hotel room keys in their Apple Wallet.
This one's a little more complex than the others because it needs to update not just the Watch but the Home app on iOS and macOS too, and you'll need a HomeKit hub. At the moment you can use an iPad for that but iOS 16 removes that feature, requiring you to have a HomePod or Apple TV device as your hub instead.