Apple Watch 'Series 4' might use bigger 384x480 resolution

That compares with the 312-by-390 resolution on the Series 3. Apple is believed to have accidentally leaked images of its successor late last month, revealing a device with a bigger display, a new watchface, and new complications. More complications can also be shown onscreen simultaneously.

After testing using Xcode's Apple Watch Simulator, assuming a density of 345 pixels per inch, 9to5Mac noted that some apps may have to make serious interface changes. The company will presumably issue this code on or around its Sept. 12 press event, when it's likely to reveal the new Watch and possibly launch watchOS 5 for existing models.

Aside from support for new hardware watchOS 5 will bring a Walkie Talkie app and native podcast support, including offline playback for both first- and third-party apps. People will also be able to launch Siri by raising their wrist, and get proactive suggestions from the Siri watchface based on daily routines.

Fitness followers will get long-awaited automatic workout detection, new Yoga and Hiking workouts, and pace alerts for people wanting to keep up a certain speed during runs and walks.

In some cases people will be able to respond to notifications without opening an app, and even preview website links.