Building a Complete FIRE Calculator App with GitHub Copilot in One Chat Session

A developer built a complete FIRE (Financial Independence, Retire Early) calculator app in 30 minutes using GitHub Copilot's agent mode in VS Code. The privacy-first PWA includes 9 different calculators (Standard FIRE, Coast FIRE, Lean/Fat FIRE, Barista FIRE, and more), works completely offline, stores no data, and was created through a single conversational chat session. The app uses React, TypeScript, Tailwind CSS, and Recharts, with all calculations happening client-side and shareable via URL parameters.