React Native App Development for Android and iOS

Developers write components in React using JavaScript or TypeScript. React Native translates these into real native views on Android and iOS, and runs the app’s logic in an optimised JavaScript engine called Hermes. The newer architecture lets JavaScript and native code communicate more directly and efficiently, which improves responsiveness and makes native modules easier to build. The result is a genuinely native app, built with web-style development productivity.

React Native is a strong choice in these situations.

Both are excellent for cross-platform apps. React Native uses JavaScript or TypeScript and native components, which suits teams with web skills and products that should look native on each platform. Flutter uses Dart and draws its own interface, which suits highly custom, brand-led designs and pixel-level consistency. Performance is good in both for typical business apps. The best choice depends mainly on your team, existing code and design goals. Our cross-platform app development guide explains the trade-offs.

Expo is a framework and set of services built around React Native. It provides ready-made modules for common device features, file-based routing, easy testing on real devices, cloud build services and over-the-air updates. Modern Expo supports custom native code through development builds and config plugins, so it no longer limits which native libraries you can use. For most new projects, we start with Expo because it speeds up delivery and simplifies upgrades; for specialised cases, a bare React Native setup is available.

Business logic, API clients, data models, validation, formatting utilities, state management and design tokens can usually be shared through a monorepo. User interface code is partly shareable: layout and styling differ between web and mobile, but component patterns and naming can align. Some teams use React Native for Web to share even more UI. We design the code structure so shared parts stay truly shared without forcing mobile and web to look identical. Our Next.js development team often works on the web side of these projects.

Over-the-air (OTA) updates deliver changes to the JavaScript code and assets directly to installed apps, without a new store release. They are valuable for urgent bug fixes and small content changes. App store rules limit what OTA updates can do: they must not change the app’s primary purpose or add features that bypass review, and native code changes always need a store release. We use OTA updates responsibly, with staged rollouts and the ability to roll back.

Many features are covered by well-maintained libraries: camera, location, maps, biometrics, notifications, file access and more. For SDKs from payment gateways, KYC providers, banks, hardware makers or analytics tools that lack good React Native support, we write native modules in Kotlin and Swift and expose them to JavaScript. This combination keeps most code shared while allowing anything a native app can do.

Performance depends on good engineering practices. We use efficient list components for long lists, avoid unnecessary re-renders, move heavy calculations off the JavaScript thread, run animations on the UI thread with Reanimated, optimise images, reduce bundle size and profile on real low-end Android devices. The Hermes engine and the new architecture help with start-up time and responsiveness.

Yes. React Native can be integrated into existing Android and iOS apps screen by screen, often called a brownfield approach. This lets companies modernise gradually or build new features once for both platforms without rewriting the whole app. It requires careful navigation and state integration between native and React Native parts, which we plan from the start.

Older React Native apps often fall many versions behind, which leads to build failures, store compliance problems with new target API levels or Xcode versions, and abandoned libraries. We audit dependencies, plan an upgrade path, replace unmaintained libraries, move to the new architecture where practical and add tests to reduce regression risk. Sometimes moving the project to Expo simplifies future upgrades considerably. Our app maintenance service keeps apps current afterwards.

We use Jest for unit tests of logic, React Native Testing Library for components, and Detox or Maestro for end-to-end tests that run full user journeys on emulators and devices. TypeScript catches many errors before runtime. Manual testing on a range of Android phones and iPhones completes the picture before each release.

We build a shared component library with your brand styles, then adapt details for each platform: navigation patterns, headers, back behaviour, date pickers, alerts, haptics and typography. This gives a consistent brand while respecting what Android and iPhone users expect. Our app UI/UX design team defines where to share and where to differ.

Yes, with the right practices. Sensitive data is stored in the platform Keychain or Keystore, network connections are encrypted with certificate pinning where appropriate, secrets are kept on the server, JavaScript bundles are protected against tampering, and biometric authentication is used for sensitive actions. As with any app, the back end enforces security. Our enterprise mobile app development service covers additional controls such as device management.

We keep state management simple. Server data is handled with TanStack Query, which manages caching, loading states and background refreshes. Local app state uses lightweight tools such as Zustand, or Redux Toolkit for complex apps. Offline data can be stored in SQLite-based or key-value storage. Choosing a small, consistent set of tools keeps the codebase easy for new developers.

These issues are common in apps we are asked to rescue.

Apps are built and signed for each platform, often using cloud build services, then published to Google Play and the App Store following their policies. We set up automated pipelines that build, test and submit releases, with staged rollouts and monitoring through crash reporting tools. OTA updates handle small fixes between store releases.

JavaScript and React are among the most widely known technologies in India, so React Native projects draw on a large talent pool. Web developers can contribute to mobile work after learning mobile-specific patterns. A codebase that uses TypeScript, common libraries and clear structure makes onboarding new developers or switching partners much smoother.

Costs depend on the number of screens and user roles, design complexity, native modules and SDK integrations, sharing with an existing web codebase, back-end and admin needs, offline and real-time features, testing scope and release automation. Sharing one codebase usually costs less than building two separate native apps. Our app development cost guide covers the main factors.