A similar question was asked about tvOS, my answer at #47928 (comment) is also applicable to watchOS. Substitute "tv" with "watch" as you read 🙂

It would involve code changes in the buildroot, and some changes to Dart and Skia (if we aren't totally off Skia and onto Impeller by then).

Most of the work would be adding an entirely new embedder in the engine, as well as test harnesses. We are working on some refactoring in the Flutter engine that should, in theory, allow more code to be shared between macOS, iOS, and future embedders like tvOS or watchOS. I would also expect some new fresh gotchas around platform view and threading models.

To get it working from flutter_tool and not just Xc…