I Built an iPhone App in Four Days with Anthropic’s Frontier Model
Summary
This article documents building an iPhone app in four days using Claude Opus 5.5, detailing planning, auto-generated code via Claude Code, testing on-device, and iterative refinements. It highlights cost-effective AI-driven development (about $4 in API calls) and a 80% to 99% improvement in accuracy after a targeted benchmark. It emphasizes intentional design, human oversight, and practical tips for SMB developers exploring AI-powered app creation.