watchOS 27 is designed primarily to make the Apple Watch smarter. This starts with the home screen, which now displays the brand-new Siri AI app in the center, with six recently used apps arranged in a ring around it. After the update, the Smart Stack can also display information such as ongoing Siri conversations or the location of parked vehicles.
A tap gesture, where you tap your thumb and index finger together, lets you scroll through the Smart Stack. In watchOS 27, Siri AI is also a standalone app on the Apple Watch, allowing you to view and resume past conversations. The voice assistant is now implemented as an AI chatbot and is designed to answer questions similarly to ChatGPT, though Siri AI can also start navigation, play music, or send a text message.