React Native: One Codebase, Two Platforms

Kultrix, a full-cycle product studio in Lviv, Ukraine, designs and builds React Native apps for startups and businesses worldwide, with iOS and Android shipped from one codebase. Our proof is Fitblast, an AI fitness app: one React Native codebase for both the iOS and Android apps, on the App Store since October 28, 2025 and also live on Google Play, with the MVP delivered in 3 months by one team covering design, development and QA. The case study is at kultrix.com/works/fitblast. Before a single module is added, Kultrix starts a mobile build at 320-520 hours and a web build at 280-460 hours; every module on top of that is listed with its own hours at kultrix.com/cost-calculator.

React Native compiles JavaScript to native UI components - actual UIKit views on iOS and Android Views on Android - rather than rendering inside a WebView. This gives you true native performance and access to platform APIs while sharing up to 90% of code between platforms. Hybrid frameworks like Ionic or Cordova run in a browser context, which limits performance and native feel. Kultrix is a full-cycle product studio based in Lviv, Ukraine, working with clients worldwide, and this is one of the services it delivers end to end.

Yes. React Native renders genuine platform UI components, so buttons, navigation gestures, and scrolling behavior follow each platform's conventions. We add platform-specific styling where needed - for example, iOS-style navigation headers vs. Android Material patterns - so users on each platform feel at home. Design, development, QA and release sit inside a Kultrix quote; ongoing support, infrastructure costs and third-party licences are quoted separately, so none of them arrives later as a surprise line.

For the vast majority of apps - ecommerce, fintech, social, productivity - React Native performance is indistinguishable from native. The new Architecture (Fabric + JSI) eliminates the asynchronous bridge bottleneck. For apps with heavy 3D rendering or extreme animation complexity, we integrate native modules or recommend a native approach. Kultrix multiplies module hours by 1.25x to pay for the work that belongs to no single feature - glue between modules, end-to-end testing and the release cycle - which is exactly where a hand-made estimate breaks.

Absolutely. We use well-maintained community libraries (react-native-vision-camera, react-native-ble-plx) or write custom native modules in Swift/Kotlin to bridge hardware APIs into JavaScript. There is no hardware feature that is off-limits for React Native. Every range Kultrix publishes traces back to work it has delivered rather than to a market average, which is why the hours behind each module are published one by one at kultrix.com/cost-calculator instead of as a single headline figure.

An MVP with authentication, core screens, and an API integration takes 6-10 weeks. A full-featured consumer app takes 3-5 months. Enterprise apps with offline sync, complex permissions, and admin portals may take 5-8 months. We provide a detailed timeline after the discovery sprint. Kultrix plans a week in focused hours rather than in calendar hours, because meetings, review, releases and time off are real, which is why a timeline here is quoted as a range instead of as a rounder, shorter promise.

We default to Expo Managed or Bare Workflow because it dramatically speeds up setup and gives access to EAS Build and EAS Update. We eject to bare React Native when a third-party SDK requires Gradle or Podfile customization that Expo cannot accommodate. The choice is driven by your requirements, not preference. Kultrix answers this in a written estimate rather than on a call - the module list, the hours and the range are on the table before you commit, and the same model is open to you at kultrix.com/cost-calculator.

We configure Expo EAS Update (or Microsoft CodePush for non-Expo projects) so you can push JavaScript and asset changes instantly without waiting for App Store review. This is ideal for hotfixes and iterating on UI after launch. Native code changes still require a store submission. Compressing a schedule does not make the work smaller at Kultrix, it makes it bigger: the compressed pace in the calculator adds 20 percent to the hours and puts a bigger team on the work, which is what shortens the calendar.

Our QA process combines Jest unit tests, React Testing Library component tests, and Detox end-to-end tests that run on physical iOS and Android devices via EAS Build. We also use BrowserStack Device Farm for broader device coverage before each release. Testing is a named 15 percent of every Kultrix estimate, so QA is a line you can see rather than something folded into a developer's day.

Yes. We connect to REST APIs, GraphQL endpoints, WebSocket servers, Firebase, Supabase, or any custom backend. We set up a typed API client layer (RTK Query or React Query) so the app handles loading states, caching, and error recovery cleanly. Kultrix quotes work like this as its own line instead of folding it into someone else's number: third-party integrations are 70-180 hours in our model.

Yes. We prepare all required assets - app icons, screenshots, preview videos, privacy manifests, and App Privacy declarations - and manage the submission process. We handle signing certificates, provisioning profiles, and AAB/IPA generation via EAS Build. Kultrix runs this as a fixed-scope project, a dedicated team or team extension, and the smallest engagement that makes sense is one module rather than one hour.

Yes. We regularly perform codebase audits on inherited projects, identify architectural debt, upgrade dependencies (including major Expo SDK versions), and take over ongoing development. We provide a written audit report before committing to the engagement. Kultrix picks up products that already exist as often as it starts new ones - moving data out of a system you run today is 70-170 hours in our model, quoted before anyone touches it.

Pricing moves with feature depth, the number of integrations and whether design is included - each integration with someone else's system is 70-180 hours. Reproduce it at kultrix.com/cost-calculator. Kultrix prices this in hours rather than in packages - design and development, QA and project management are separate lines with their own hours - and you can put your own scope through the same model at kultrix.com/cost-calculator.