Building a Mobile App with OpenAI Codex (Better than Claude Code)

I built a Swift iOS app that builds apps.. a better, simpler alternative to Replit, built entirely without writing code. Using OpenAI's Codex desktop app, Xcode, and the Claude Agent SDK (Claude Code SDK), I created "Jerry" which is an iMessage style vibe coding app that generates and hosts web and mobile apps through natural conversation. In this video, I walk through the entire process: -designing the UI in Paper (a Figma alternative for AI agents), -building the Swift app with Codex, -integrating the Claude Agent SDK for AI-powered app generation, -connecting the Vibecode CLI for hosting, -and adding voice input with OpenAI Whisper Tools used in this build: - OpenAI Codex (desktop coding app): https://openai.com/codex - Claude Agent SDK (Anthropic): https://docs.anthropic.com - Vibe Code CLI: https://vibecode.dev - Paper (AI-native design tool) - Xcode + Swift - OpenAI Whisper (voice input) Where to find my other content: https://x.com/rileybrown https://www.linkedin.com/in/riley-brown-7441b1101/ https://www.instagram.com/realrileybrown/ https://www.tiktok.com/@rileybrown.ai TIME STAMPS 00:00 Intro 00:38 Why I'm Replacing Replit 01:35 The Jerry App Concept & Prompt 03:35 Setting Up Xcode & Codex 06:08 Designing the UI with Paper 10:54 First Build & Testing on iPhone 14:58 Integrating Vibe Code CLI 17:32 Testing Real App Generation 24:40 Adding Voice Input 26:44 Final Demo #vibecoding #replitalternative #codex