React Native App Development UK

When React Native is the right choice

React Native lets you build native mobile apps with React and TypeScript. The screens are real platform views, not a web page in a wrapper. It makes most sense when your business already has a React or Next.js web application, or a team that knows React, because the mobile app can share validation rules, API types and much of the business logic with the web. One change to a pricing rule then lands in both places.

If your app needs pixel-identical custom design across every device and you have no existing React code, Flutter is often the better fit. We compare both honestly; see mobile app development for the wider picture.

The New Architecture and why upgrades matter

The React Native blog records that version 0.82, released on 8 October 2025, was the first to run entirely on the New Architecture, with the option to switch it off removed. Version 0.84 in February 2026 made Hermes V1 the default JavaScript engine, and releases have continued every couple of months since. The New Architecture replaces the old asynchronous bridge with JSI, the Fabric renderer and TurboModules, which gives faster start-up and synchronous calls into native code.

Apps written before 2024 often depend on libraries that never supported the new system. Those apps can no longer move to current React Native versions, and therefore struggle to meet Apple's Xcode requirement or Google Play's target API level. We migrate them library by library, replace abandoned packages, and rewrite small native modules where needed.

How we build React Native apps

• Expo for the development workflow and native modules, with EAS Build producing signed iOS and Android builds in the cloud.
• TypeScript throughout, with API types generated from your OpenAPI spec and shared with the web app in a monorepo.
• Navigation with React Navigation or Expo Router.
• Data through TanStack Query with offline caching, and SQLite for data that must survive without signal.
• Secure storage of tokens in the Keychain and Keystore.
• Testing with Jest for logic and end-to-end tests on real devices.

Updates without waiting for the store

Because much of a React Native app is JavaScript, Expo's EAS Update can deliver small fixes, such as a corrected label or a changed validation rule, straight to users' devices without a full store release. Both Apple and Google allow this for changes that do not alter the app's purpose or add new native features, so we use it for fixes and keep feature releases going through review. Every over-the-air update is versioned and can be rolled back.

The app talks to a secure API, usually Laravel or Node.js, that connects to your other systems. See API development and React development.

Performance and native features

Slow React Native apps are usually slow for fixable reasons: long lists rendered without virtualisation, heavy work on the JavaScript thread during animations, or too many re-renders from global state. We profile with React Native DevTools, use FlashList or FlatList correctly for long lists, move animations onto the UI thread with Reanimated, and keep state local where it belongs.

When a feature has no maintained library, such as a manufacturer's barcode scanner SDK or a Bluetooth label printer, we write a small native module in Swift and Kotlin using Expo Modules or TurboModules. Keeping these modules small and well documented means the next framework upgrade does not turn into a rewrite.

Security follows the same rules as any mobile app: no secrets in the JavaScript bundle, tokens in secure storage, certificate checks on API calls, and sensitive screens hidden from the app switcher. We also keep an eye on start-up time, since Hermes V1 and precompiled builds help but large bundles still cost seconds.

Getting started

Tell us about the app you need, or the one you already have. For new builds we scope a first release and quote a fixed price. For existing apps we begin with a code audit covering the React Native version, libraries and build setup, then quote the upgrade. Ongoing upkeep is covered by app maintenance. Book a free chat.

What we deliver

• A React Native app in TypeScript for iPhone and Android
• Shared packages for types, validation and API calls used by web and mobile
• Expo and EAS Build setup with signed builds for both stores
• Offline storage and background sync where needed
• Migration of older apps to the New Architecture
• Store listings, submission and release management

How it works and what it costs

Every project gets a fixed-price quote after a free initial chat and a short scoping stage. You own the code and the data.

1. Free chat

   Tell us the problem in plain English: what you do now, what goes wrong and what "better" looks like. No charge, no obligation.

2. Scoping

   We map the processes, systems and data involved, agree what is in and out, and write it down so there are no surprises.

3. Fixed-price quote

   You get a fixed price for the agreed scope, or a phased plan for bigger builds, so you can start small and prove it works.

4. Build and test

   We build in short stages you can see and try, test against real data, then go live carefully with a rollback plan.

5. Hand over and look after

   You own the code and the data. We can host it, support it and keep improving it, or hand it to your own team.

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