A Guide to React Native Development: Build Cross-Platform Apps

See, when you are trying to create a mobile app, what’s the key requirements? That it should be fast, cost-effective (to build), and scalable. And ideally, the app should work on both iOS and Android with a single codebase while maintaining native performance. React Native delivers exactly that.

React Native is used by giants like Facebook and Instagram and is a game-changer. Businesses can reach both iOS and Android users without doubling their development efforts.

So through this blog, we’ll focus on React Native development. You’ll learn how the React Native experts leverage the platform’s strengths and navigate the pitfalls to deliver high-quality apps efficiently.

What is React Native?

React Native is an open-source framework for building cross-platform mobile apps using JavaScript and React. It was built by Meta (formerly Facebook) and lets developers write code once and deploy it on both iOS and Android. That significantly reduces the development time and cost alike.

Unlike hybrid frameworks, React Native renders native components. That ensures near-native performance and a smoother user experience.

With React Native, you get hot reloading for faster iterations, along with strong community support. That’s why apps like Instagram, Airbnb and Uber Eats prefer it. So whether you want a startup or an enterprise, React Native offers a scalable solution without sacrificing quality.

React vs React Native

Let’s take a look at the code comparison.

React (Web)

// Web: Styling with CSS
import './App.css';

function App() {
  return (
    <div className="container">
      <h1>Hello Web</h1>
      <button onClick={() => alert("Clicked!")}>Press</button>
    </div>
  );
}

React Native (Mobile)

// Mobile: Styling with JavaScript
import { View, Text, Pressable, StyleSheet } from 'react-native';

function App() {
  return (
    <View style={styles.container}>
      <Text style={styles.title}>Hello Mobile</Text>
      <Pressable onPress={() => alert("Clicked!")}>
        <Text>Press</Text>
      </Pressable>
    </View>
  );
}

const styles = StyleSheet.create({
  container: { flex: 1, padding: 20 },
  title: { fontSize: 24 }
});

While there are some key differences between React and React Native, can they work together? Well, the answer is yes. With React Native for Web, you can write components that work on web + mobile. And you can share business logic between platforms with ease.

Pros & Cons of React Native Development

React Native is one of the top mobile app development platforms that comes with its fair share of pros and cons. So let’s discuss them in spades.

Pros of React Native

• Cross-platform Efficiency: Write once, run on both iOS and Android, reducing development time and cost.
• Near-native Performance: Uses native components instead of web views, delivering smoother UX.
• Hot Reloading: Instantly see code changes without full app rebuilds, speeding up development.
• Strong Community & Ecosystem: Backed by Meta, supported by a vast library of third-party plugins.
• Cost-effective: Single codebase means fewer developers and easier maintenance.
• Reusable Code: Share logic between web (React.js) and mobile apps.

Cons of React Native

• Performance Limitations: Heavy animations or complex computations may still require native modules.
• Native Dependency Risks: Some features need platform-specific code, reducing cross-platform benefits.
• Debugging Challenges: Issues can be harder to trace due to the bridge between JavaScript and native threads.
• Long-term Maintenance: Frequent updates may require adjustments to third-party libraries.
• Larger App Size: Slightly bigger than fully native apps due to the JavaScript runtime.

React Native is ideal for MVP startups, mid-sized apps, and businesses prioritizing speed and cost. But on the flip side, it may not be the most suitable platform for high-performance gaming or CPU-intensive apps.

You can of course consult with a professional React Native development company to get a better idea on how these pros and cons will affect your project.

How Does React Native Work?

React Native is an excellent platform, in that it bridges JavaScript and native mobile platforms. Developers can use it to build apps using React’s declarative UI approach while leveraging native performance.

JavaScript Thread & Native Thread

The app runs in two parallel threads:

• JavaScript thread: Executes your React logic and business code.
• Native (UI) thread: Handles rendering and native APIs (like camera, GPS).

They communicate asynchronously via a bridge, serializing JSON messages.

The React Native Bridge

Translates JavaScript calls into native module commands (e.g., rendering a <View> as an iOS UIView or Android ViewGroup). It’s optimized for performance but can become a bottleneck for high-frequency updates (e.g., animations).

Native Components, Not WebViews

Unlike hybrid frameworks (e.g., Cordova), React Native directly renders platform-specific UI components (e.g., Switch becomes UISwitch on iOS). Developers can also write custom native modules (Java/Kotlin, Swift/Obj-C) for unsupported features.

Just-In-Time (JIT) vs. Ahead-of-Time (AOT) Compilation

On Android, JavaScript is compiled at runtime (JIT). On iOS (due to JIT restrictions), it’s precompiled (AOT) for better startup performance.

UI Updates with Virtual DOM

Like React, it uses a reconciliation algorithm to compute minimal UI changes, reducing unnecessary re-renders.

New Architecture (Fabric & TurboModules)

There are two components of the new architecture:

• Fabric: Replaces the bridge with direct C++ communication, improving rendering speed.
• TurboModules: Lazily loads native modules, reducing startup time.

Apps feel native, with most code shared across platforms. And you can still do fine-tuned native optimizations with React Native development.

How to Develop React Native Mobile Apps?

Developing a React Native app involves setting up your environment, writing cross-platform code, testing, and deploying. Here’s a structured approach:

Prerequisites for React Native Development

Before starting the React Native development process, there are some prerequisites to handle.

• Basic knowledge of JavaScript & React
• A development machine (Windows, macOS, or Linux)
• Node.js & npm/yarn (for package management)
• Python 2/3 & JDK 8 (for Android development)
• Android Studio (for Android) or Xcode (for iOS)

Step 1: Install NodeJS Python JDK 8

First off, you need to install NodeJS, Python, and JDK 8.

Node.js

It’s required to run JavaScript and manage dependencies via npm/yarn. Download the LTS version from NodeJS official website.

After downloading, verify with:

node --version  # Should show v18.x or higher
npm --version   # Bundled with Node.js

Python

It’s needed for native module compilation for Android. You may download it from the official Python website. The Python version should be according to your React Native version’s requirements.

After downloading, verify with:

python --version

JDK 8 (Java Development Kit)

JDK is required for Android app projects due to Gradle dependency. You can download it from Oracle or use OpenJDK. In the latter case, set the JAVA_HOME environment variable to the JDK path.

After downloading, verify with:

java -version  # Should show 1.8.x

JDK installation can be skipped if you’re only targeting iOS (macOS/Xcode).

Step 2: Install React Native CLI (Optional)

For global project creation, install the CLI:

npm install -g react-native-cli

Newer React Native versions use npx, so there’s no need for global install.

Step 3: Create Your React Native Project

Use the React Native CLI or npx:

npx react-native init MyApp

This sets up a new project with a default template.

Step 4: Run the React Native Project

Start the Metro bundler (JavaScript bundler):

cd MyApp && npx react-native start

In another terminal, run the app:

Android

npx react-native run-android

iOS

npx react-native run-ios

Step 5: Install Android Studio (for Android) or Xcode (for iOS)

Now we come to the development environment. For Android, it’s Android Studio and for iOS, it’s Xcode (macOS only).

Android Studio

You can install it from the Android Studio official website. Set up an Android Virtual Device (AVD) for emulation.

Xcode

You can install it from the Mac App Store. Then open ios/MyApp.xcworkspace to configure iOS builds.

Step 6: Write Your App Code

When developing a React Native app, you’ll primarily work with:

• Core Components (View, Text, Button, etc.)
• Styling (Flexbox-based stylesheets)
• State Management (useState, useEffect hooks)
• Navigation (React Navigation library)
• Platform-specific Code (when needed)

Here’s a complete example of a simple calculator app:

First, let’s start with the imports and setting up the component structure:

import React, { useState } from 'react';
import { StyleSheet, View, Text, SafeAreaView } from 'react-native';
const Calculator = () => {
  const [currentValue, setCurrentValue] = useState('0');
  const [previousValue, setPreviousValue] = useState(null);
  const [operation, setOperation] = useState(null);
  return (
    <SafeAreaView style={styles.container}>
      <View style={styles.displayContainer}>
        <Text style={styles.previousText}>
          {previousValue} {operation}
        </Text>
        <Text style={styles.currentText}>{currentValue}</Text>
      </View>
    </SafeAreaView>
  );
};

Now we need to add buttons for numbers and operations along with logic for handling input and calculations.

const handleNumberPress = (number) => {
  if (currentValue === '0') {
    setCurrentValue(`${number}`);
  } else {
    setCurrentValue(`${currentValue}${number}`);
  }
};
const handleOperationPress = (op) => {
  if (currentValue === '0') return;
  if (operation && previousValue) {
    const result = calculate();
    setPreviousValue(result);
  } else {
    setPreviousValue(currentValue);
  }
  setCurrentValue('0');
  setOperation(op);
};
const calculate = () => {
  const prev = parseFloat(previousValue);
  const current = parseFloat(currentValue);
  if (isNaN(prev) || isNaN(current)) return '0';
  switch (operation) {
    case '+': return (prev + current).toString();
    case '-': return (prev - current).toString();
    case '*': return (prev * current).toString();
    case '/': return (prev / current).toString();
    default: return currentValue;
  }
};

Once the logic part is done, we can render all buttons in rows, style everything properly and use a reusable Button component.

const Button = ({ title, onPress, isOperation, isZero }) => (
  <TouchableOpacity
    style={[
      styles.button,
      isOperation && styles.operationButton,
      isZero && styles.zeroButton
    ]}
    onPress={onPress}
  >
    <Text style={[
      styles.buttonText,
      isOperation && styles.operationButtonText
    ]}>
      {title}
    </Text>
  </TouchableOpacity>
);

While this code serves as a complete app with basic calculator functions, you can extend it effectively.

Step 7: Test Your App

Testing is crucial for ensuring app quality and stability. React Native apps should be tested at multiple levels:

Unit Testing

Tests individual functions/components in isolation.

What to Test?

• Utility functions
• Business logic
• Component rendering
• State management

Example (with the calculator app)

// calculator.test.js
import { calculate } from './calculator';
test('adds 1 + 2 to equal 3', () => {
  expect(calculate('1', '2', '+')).toBe('3');
});
test('divides 6 by 3 to equal 2', () => {
  expect(calculate('6', '3', '/')).toBe('2');
});

Component (Integration) Testing

Tests React components and their interactions.

What to test?

• Component rendering
• User interactions (button presses, etc.)
• Props and state changes

Example (with the calculator app)

import { render, fireEvent } from '@testing-library/react-native';
import Calculator from './Calculator';
test('number button updates display', () => {
  const { getByText, getByTestId } = render(<Calculator />);
  fireEvent.press(getByText('5'));
  expect(getByTestId('display').props.children).toContain('5');
});

End-to-End (E2E) Testing

Tests complete user flows across the app.

What to test?

• Navigation between screens
• Complex user interactions
• API calls and data persistence

Example (for the calculator app)

describe('Calculator', () => {
  it('should calculate 2+2', async () => {
    await device.launchApp();
    await element(by.text('2')).tap();
    await element(by.text('+')).tap();
    await element(by.text('2')).tap();
    await element(by.text('=')).tap();
    await expect(element(by.text('4'))).toBeVisible();
  });
});

Step 9: Deploy to App Stores

After your React Native-based app is ready and tested, it’s time to deploy it to the Google Play Store and App Store. Here’s how you do it.

Android (Google Play Store)

– Generate a release APK/AAB:

cd android && ./gradlew assembleRelease

– Sign the app & upload to Google Play Console.

iOS (Apple App Store)

– Archive the app in Xcode.

– Submit via App Store Connect.

This process can be quite comprehensive and a bit too technical for those without the necessary skills and expertise. In that case, you’ll be better off with professional React Native app developers.

Best Practices for React Native Development

React Native enables fast, cross-platform app development—but following best practices ensures performance, maintainability, and scalability. Here’s how you build high-quality React Native apps.

Use Functional Components & Hooks

Opt for functional components with hooks (useState, useEffect) over class components. They’re cleaner, more performant, and align with modern React practices.

Optimize Rendering with Memoization

Prevent unnecessary re-renders using React.memo, useMemo, and useCallback. This boosts performance, especially in complex UIs.

Modularize Your Codebase

Split code into reusable components, hooks, and utility functions. A well-organized structure (e.g., feature folders) scales better.

Adopt TypeScript for Type Safety

TypeScript catches errors early and improves code maintainability. Define interfaces for props, state, and API responses.

Minimize Bridge Calls

Reduce communication between JavaScript and native threads. Batch operations and avoid frequent state updates in loops.

Use Platform-specific Optimizations

Leverage platform extensions (.ios/.android.js) for OS-specific designs or logic. Test on both iOS and Android early.

Optimize Images & Assets

Compress images, use vector icons (e.g., react-native-svg), and lazy-load heavy assets to reduce bundle size.

Implement Secure Storage

Never store sensitive data in AsyncStorage. Use encrypted alternatives like react-native-keychain or Expo SecureStore.

Profile Performance Regularly

Use Flipper, React Native Debugger, or the Performance Monitor to identify bottlenecks (e.g., slow navigation, memory leaks).

Write Unit & Integration Tests

Cover core logic with Jest and component tests (React Testing Library). For E2E flows, use Detox or Maestro.

These practices ensure your app is fast, maintainable, and production-ready.

FAQs on React Native Development

Let’s Conclude

React Native bridges the gap between cross-platform efficiency and native performance. It offers a powerful solution for building mobile apps without sacrificing quality. With React Native, you can launch apps quickly or streamline the development with flexibility and a robust ecosystem.

There are, of course, some challenges like performance tuning and platform-specific tweaks. But benefits like faster development, cost savings, and a single codebase far outweigh the hurdles.

If you want help with ensuring the best cross-platform development, connect with our React Native professionals today!