ZDNET's David Gewirtz used Claude Code to build an Apple Watch app in about 12 hours

ZDNET writer David Gewirtz used Anthropic's Claude Code to develop an Apple Watch version of his filament management app, producing a working app in about 12 hours of actual work time spread over roughly three weeks. Gewirtz said the challenge was reducing the iPhone app to a tiny, usable watch experience.

He asked Claude Code for feature recommendations, rejected NFC and photo capture for the Watch, and settled on a compact set of capabilities: browse and filter spools by material, color, and vendor; view spool details and current assignment; move spools between machines and storage; mark spools as complete; browse machines, storage locations, and colors; and dynamically sync data between phone, Mac, and watch.

He also chose to omit many iPhone features, including NFC-based workflows, full spool management, editing reference data, backup and restore, and settings tools. Early prototyping produced a usable interface in about two hours, but testing on a physical Apple Watch with 120+ data records exposed memory and sync problems.

Gewirtz noted his Apple Watch Series 9 has 1GB of RAM and 64GB of storage, and said iCloud sync initially brought down all photo data at once, overwhelming the device. Rather than fully rearchitect the apps, he and Claude Code split the data structures so the Watch version excluded photos, which resolved the issue and yielded a working app.

Key Topics

Tech, Claude Code, David Gewirtz, Apple Watch, Anthropic, Filament Management