What is a cross-platform app?

Cross-platform app: definition

Instead of programming a separate app for each platform, developers write most of the code only once. A framework compiles this code or embeds it so that it runs on iPhones and Android devices—and with some frameworks, also on the web or on desktop.

Like native apps, cross-platform apps are distributed via the App Store and Google Play and installed on the device. With well-built apps, users usually can't tell the difference.

How cross-platform development works

Frameworks take different approaches: some draw the interface themselves, others use the system's native controls, and still others wrap a web application in an app shell. For features the framework doesn't cover, native code can be added where needed.

• Flutter (Google): Dart programming language, its own rendering engine
• React Native (Meta): JavaScript/TypeScript, uses native controls
• .NET MAUI (Microsoft): C# for mobile and desktop apps
• Kotlin Multiplatform: shared logic, with an optional native interface
• Capacitor: packages web applications as installable apps

Benefits and limitations of cross-platform apps

The biggest benefit is cost-effectiveness: one codebase means less development effort, a single team, and new features that appear on both platforms at the same time. Bug fixing and maintenance are consolidated as well.

Limitations show up with software that works very close to the hardware or is graphically demanding, and when new operating system features are needed right away. There is also a dependency on the chosen framework and its continued development—one reason to rely on established, actively maintained solutions.

• Less effort than two native apps
• Consistent look and the same feature set
• One team, one codebase, consolidated maintenance
• Special features may require additional native code

Real-world example: a customer app for iOS and Android

A driving school wants to offer its students an app with practice questions, appointment booking, and progress tracking—on iPhone and Android alike. A cross-platform app built with Flutter or React Native covers all features, accesses the backend via an API, and reaches both stores with a single development track. Later extensions such as push notifications or a payment area are also developed only once.

For most business and customer apps, this approach strikes a good balance between quality and budget. Nano Concepts develops cross-platform apps including the backend and supports publication in the App Store and Google Play.