The Apple Watch may support third-party watch faces in the future
Third-party watch faces for smartwatches allow users to express more of themselves while also letting them have a bit more fun with their tech. The Apple Watch already has a number of Apple-made watch faces, many of which are customizable, but third-party developers haven't been able to make their own. A report from 9to5Mac suggests that might change soon, thanks to code found in watchOS 4.3.1 hinting at third-party watch face compatibility.
The interesting log message states: "This is where the 3rd party face config bundle generation would happen." It's part of the NanoTimeKit framework in the wearable software beta, which gives developers access to watch face components. While the feature doesn't appear to be active yet, it seems to refer to an inactive developer tool server that may allow communication with Xcode on macOS.
It's unclear if Apple would make this feature active in watchOS 5, the next version of the Apple Watch's software that's expected to be announced at WWDC this June. Even if Apple doesn't announce it as a feature in watchOS 5, the mere mention of it means it's possible that the company would allow third-party developers to create clock faces for its wearable sometime in the future.