Cross-Platform & Multi-Platform App Development: React Native vs Flutter

Updated September 2026 · Written and maintained by the Progression Agency strategy team

Cross-platform app development means building one app that runs on both iPhone and Android from a single codebase. It is now the default choice for most business apps, and it is the approach Progression Agency recommends most often. This page explains how cross-platform development works, how it compares with native and hybrid apps, when React Native or Flutter is the better framework, what it costs, and when native is still worth it.

What is cross-platform app development?

Cross-platform app development is building a mobile app from one shared codebase that compiles or renders natively on both iOS and Android. Frameworks such as React Native and Flutter let one team write the app once and publish it to both the App Store and Google Play.

Unlike older hybrid approaches that displayed a website inside an app shell, modern cross-platform frameworks render real native components (React Native) or draw every pixel with a high-performance engine (Flutter). For most business apps users cannot tell the difference from a native build.

Cross-platform vs native vs hybrid app development

Native apps are built separately for each platform in Swift and Kotlin and offer the best performance and hardware access at the highest cost. Cross-platform apps share one codebase with near-native performance at lower cost. Hybrid apps wrap web code in a native shell and are the cheapest but the least app-like.

What is the difference between cross-platform and hybrid?

A hybrid app is a web application running inside a native wrapper, typically using Ionic with Capacitor or Cordova. A cross-platform app uses a framework that produces native UI or its own compiled rendering. Cross-platform apps generally feel and perform closer to native.

React Native vs Flutter: which should you choose?

Choose React Native if your team knows JavaScript or TypeScript and React, if you want to share logic with a React web app, or if you rely on the large npm ecosystem. Choose Flutter if you want a highly branded interface that looks identical on both platforms, smooth custom animation, or a single toolkit that also targets web and desktop.

What about Kotlin Multiplatform?

Kotlin Multiplatform shares business logic between platforms while keeping each platform’s native interface, and Compose Multiplatform extends sharing to UI. It suits teams with strong Android and Kotlin skills who want native UI with shared logic. See the Kotlin Multiplatform documentation.

Pros and cons of cross-platform development

• Pro: one codebase for iOS and Android reduces build and maintenance effort.
• Pro: simultaneous launch on both stores with feature parity.
• Pro: one team to hire and manage.
• Pro: faster iteration — fixes and features ship to both platforms together.
• Con: some platform-specific features need native modules.
• Con: framework and dependency upgrades must be kept current.
• Con: app bundles can be larger than an equivalent native app.

When should you build native instead?

Build natively when performance-intensive graphics, augmented reality, complex background processing or brand-new OS features are the core of the product, or when you need only one platform. For most other apps, cross-platform is the better investment.

How much does cross-platform app development cost?

As a planning range, a cross-platform MVP commonly costs roughly $40,000-$90,000 and a full-featured business app roughly $90,000-$200,000. Compared with two separate native builds, cross-platform commonly saves a substantial share of the build and maintenance budget because most code is written once.

See the full app development cost breakdown for cost by app type and feature.

Our cross-platform app development services

Progression Agency builds cross-platform apps in React Native and Flutter, with the backend, admin tools, store launch and user acquisition handled by the same team. We recommend the framework after discovery, based on your product and team rather than a house preference. Learn more on our app development company page.

• Framework selection and technical architecture
• UX and UI design adapted to iOS and Android conventions
• React Native and Flutter development
• Native modules for camera, payments, health data, Bluetooth and more
• Backend, APIs and admin panel
• App Store and Google Play submission
• Maintenance, OS updates and framework upgrades
• Launch marketing and app store optimization

Multi-platform app development company

A multi-platform app development company builds one product for iPhone, Android and often the web from shared code. React Native application development and Flutter are the two main routes; we choose between them per project.

Mobile app development with React

Mobile app development with React means React Native: the same component model and TypeScript skills used for React web apps, rendering real native interface elements on iOS and Android.

Other cross-platform frameworks worth knowing

Beyond React Native and Flutter, several frameworks target both platforms. Each suits a specific kind of team.

.NET MAUI

Microsoft’s framework for building native apps in C# and .NET, a natural fit for organizations already standardized on the Microsoft stack. Documentation.

Ionic with Capacitor

Builds apps from web technologies and packages them natively; efficient for teams with strong web skills and content-led apps.

Compose Multiplatform

JetBrains’ extension of Jetpack Compose that shares UI across Android, iOS, desktop and web alongside Kotlin Multiplatform logic.

NativeScript

Gives JavaScript and TypeScript direct access to native platform APIs; used by teams wanting native API access without writing Swift or Kotlin.

Testing cross-platform apps

One codebase still has to be tested on both platforms and across device sizes and OS versions. We combine automated unit and integration tests with device-farm testing and manual QA on real iPhones and Android phones.

Automated testing

Unit tests for business logic, component tests for the interface and end-to-end tests for key journeys run on every change.

Real-device testing

We test on a matrix of recent and older iPhones and popular Android devices, because performance and layout issues often appear only on specific hardware.

Beta distribution

TestFlight for iOS and Google Play testing tracks for Android put builds in real users’ hands before release.

Framework upgrades

React Native and Flutter release regularly. Maintenance plans include scheduled framework upgrades so the app never falls far behind.

Video: React Native, Flutter and Kotlin Multiplatform

Short explainers on each framework compared on this page, including Flutter’s own architecture overview.

• 

  React Native in 100 Seconds
  Fireship · 2021-09-28

• 

  Flutter in 100 seconds
  Fireship · 2020-04-14

• 

  How Flutter Works: Architecture #DecodingFlutter (1/6)
  Flutter · 2025-04-29

• 

  Dart in 100 Seconds
  Fireship · 2021-10-13

• 

  Kotlin Multiplatform Tutorial for Beginners – Your First KMP App
  Kotlin by JetBrains · 2021-03-18

• 

  Kotlin in 100 Seconds
  Fireship · 2021-11-05

Frequently asked questions