What's new in Apple's latest software update for the Apple Watch

Apple unveiled the newest version of its Apple Watch software, WatchOS 4, at its annual developer's conference on Monday.

The new software will have improved fitness tracking, new and more customizable watch faces, better Siri integration, and helpful updates to the Apple Music app.

Here are some of the major updates:

• Three new watch faces: "Toy Story" faces, Kaleidoscope Face, and Siri Face
• Personalized fitness notifications: You'll get an achievement update every morning that encourages you to meet your fitness goals
• Monthly fitness challenges
• Celebratory animations when you meet your goals
• Improved Fitness app: A new user interface, the option to "quickstart" a workout at the top of the screen, additions to the swimming workout, and a high-intensity interval training workout added
• Two-way data exchange with gym equipment: Starting this fall, the treadmill at your gym may be able to sync up with your Apple Watch via an NFC reader
• Improved Apple Music app: The app can now track music you love and sync it to the watch
• Vertical scrolling in the dock
• An improved flashlight that can also serve as a blinking safety light

And Siri...

Arguably the biggest update to the watch is the Siri integration that is now available on the watch face. Using machine learning, Apple says the watch can now check your routines and the apps you use the most, automatically displaying the on the watch face at the most appropriate times. The new Siri watch face means your Apple Watch can also serve up thing like your Wallet app, any relevant tickets or passes, and any upcoming meetings on the face depending on the time of day. And every time you raise your wrist, the watch face will update.

A developer preview of the new WatchOS 4 is available starting today, and an update will be available this fall.