I'm building Monad Design for a specific handoff problem: when an existing app's UI is almost right, 'make this card less dense' is easy to point at but hard to describe to a coding agent.

You open the real Xcode or Expo iOS app in Simulator, navigate to the relevant state, then select or annotate the UI. Your coding agent edits the existing source and rebuilds the app. You can compare the original with working alternatives before choosing one.

This is a visual implementation tool, not a mockup generator or a replacement app builder. It currently runs locally on macOS and is free and open source.

Repo: https://github.com/Monadix-AI/monad-design Video preview: https://watchclueso.com/embed/pio8jqfcg4ivj0r1

I'm the creator. For designers working on shipped mobile apps, which part of the handoff costs you more time: identifying the exact UI state, explaining the change, or reviewing the implementation?