One product model. Two native ways to use it.

Untwine is a task app for work that feels difficult to face. Emotional difficulty sits alongside priority and effort in the model; it isn’t just a color applied by the interface.

The app ships on iPhone and Mac. The underlying meaning of a task needs to stay consistent while navigation, editing, and input feel appropriate to each device.

I separate persisted models, domain logic, view state, and SwiftUI views. The shared layer holds the task data and rules; platform shells handle the interaction around them. On Mac that means a sidebar, menu commands, and keyboard shortcuts.

Sharing the product model avoids maintaining two definitions of the same task. Keeping separate shells still costs implementation and verification time, but it gives desktop interactions room to be properly native.

Task data lives locally in SwiftData. Private iCloud sync is optional and consent-based; the core experience does not require an account with me. Widgets share a constrained view of the task store rather than introducing a separate source of task truth.

That choice also creates platform work: the app and its extensions must agree on their shared container, and iOS and macOS have different sandbox requirements. A shared codebase does not remove the need to verify each shipped target.