Build Your First App with Claude Code in 20 Minutes (The Right Way) | Code with Beto

Learn how to build a real mobile app using Claude Code, Expo, and Instant DB in about 20 minutes. Unlike typical AI tutorials that only generate websites, this workflow creates a real-time React Native app that runs on iOS and Android devices with a proper backend.

You'll see how to set up your environment with Expo Go, VS Code, and the Claude Code extension, then create a new app with Instant DB as the backend. I focus on planning the app with Claude before writing code, ensuring best practices and saving tokens.

What's inside

Why most AI tutorials fall short and how this approach differs
Setting up Expo Go and Instant DB for real-time mobile development
Creating a new project folder and initializing the app with Claude Code
Running the app on iOS and Android devices using Expo Go
Installing Claude Code skills for Expo and Instant DB integration
Planning the app with Claude Code before generating any code
Building a minimalistic real-time shared to-do list app
Using Instant DB for real-time data syncing across devices

Why most AI tutorials fall short and how this approach differs

Most AI tutorials promise quick apps but only deliver websites without requiring installation or real backend setup. This wastes tokens and teaches little about real app development. This video fixes that by building a real mobile app with a real-time database backend, working on both Android and iOS.

The focus is on patterns and best practices that apply regardless of your app idea. Once you master these, you can build any app with Claude Code and Instant DB. This approach teaches you how to build properly, not just generate code snippets.

Setting up Expo Go and Instant DB for real-time mobile development

You need three main tools: Expo Go on your iOS or Android device for testing, Instant DB as the backend database, and VS Code with the Claude Code extension for development.

Expo Go lets you run your React Native app instantly on real devices without building native code. Instant DB provides a free real-time backend that syncs data safely and instantly across devices. I links to Instant DB signup and shows how to access your dashboard.

Creating a new project folder and initializing the app with Claude Code

In VS Code, create a new folder for your app and open it as your workspace. Close unnecessary sidebars for focus. Install the Claude Code extension verified by Anthropic.

Open a terminal in VS Code and run the command to scaffold your app. Select mobile with Expo as the framework and Claude as the AI. This generates the app code and creates a new backend app in Instant DB, which you can see in your dashboard.

Running the app on iOS and Android devices using Expo Go

Start the development server with . On iOS, open the camera app and scan the QR code to open the app in Expo Go. On Android, use the Expo Go app's QR code scanner.

The initial app shows a simple "hello world" screen with color picking. Changes on one device sync instantly to the other, demonstrating real-time functionality powered by Instant DB.

Installing Claude Code skills for Expo and Instant DB integration

Claude Code needs skills to understand the specific tools you're using. Install the Expo skill to guide UI creation and the Instant DB skill for backend integration.

Use commands from a linked blog post to install these skills via the terminal, selecting Claude Code as the AI. This enables Claude to follow best practices and generate code tailored to your stack.

Planning the app with Claude Code before generating any code

Rule number one: never let AI write code before it knows what it’s building. Use Claude Code’s plan mode to create a clear app plan first. This saves tokens and time.

I show how to toggle plan mode in the extension and paste a prompt describing the app: a minimalistic shared to-do list with real-time syncing, no login, tasks with emoji, title, description, status, and creation date. Styling is deferred to focus on functionality.

Building a minimalistic real-time shared to-do list app

Claude Code uses the plan to generate the app foundation. The home screen lists tasks with checkboxes using Expo Router. A bottom sheet screen allows adding new tasks with emoji and details.

The app supports multiple users seeing and updating tasks in real time without login. This simple but functional design demonstrates how to build practical apps with AI assistance and real-time backend.

Using Instant DB for real-time data syncing across devices

Instant DB handles storing and syncing task data safely and instantly. I show how changes on one device reflect immediately on another, thanks to Instant DB’s real-time capabilities.

This backend choice simplifies building collaborative apps with minimal setup and free tier usage, ideal for personal or small team projects.

Resources

CourseReact Native course

Learn React Native fundamentals and how to ship apps with best practices.

Premium resourcePro membership

Get access to exclusive tutorials, live coding sessions, and AI workflows.

Let's connect!