Solo dev builds native Swift iOS therapy app using Claude Opus 4.6 for coding, debugging, and architecture

A solo developer built Prelude, a fully offline iOS therapy preparation app, with significant help from Claude Opus 4.6. The app is free, contains no ads or in-app purchases, and stores all data on-device with zero knowledge transfer.

What the app does

Prelude runs a session agent that conducts a voice reflection session before therapy, a brief agent that generates a structured summary from the reflection, and a weekly emotional trend graph.

What Opus 4.6 handled

• Code generation for the native Swift iOS app
• Debugging complex voice agent behavior — the AI assistant worked through issues with the speech recognition and agent conversation flow
• Architecture decisions for the on-device AI pipeline — determining how to run models locally and structure data flow
• Reasoning about system design — solving problems that required genuine understanding of the full system

The developer reports that their therapist noticed improved session quality because topics were clearly listed in structured briefs they could review together.

The project would not have been possible as a solo effort without Claude handling the hardest parts.

The app is available on the App Store: Prelude – Therapy Prep