Cross-Platform UI Tools

In our last lesson, we explored the tradeoffs between native and web-based mobile interfaces. But what if you want the best of both worlds? That’s where cross-platform frameworks come in.

Today’s lesson is about building once — and deploying everywhere.

These tools aim to give you:

  • A single codebase (write once)
  • Access to native features (like notifications, GPS, storage)
  • Consistent UI across platforms (Android, iOS, web, and sometimes desktop too)

Let’s walk through some of the leading options and how to decide if cross-platform is right for you.

🌈 The Dream: One Codebase, Many Platforms

Cross-platform frameworks try to solve a fundamental developer pain:

Maintaining two (or more!) separate versions of the same app.

This used to mean compromises: clunky UI, weird bugs, slow performance. But modern tools are much more capable.

If your app doesn’t push the bleeding edge of native capabilities — cross-platform can be a great choice.

⚛️ React Native

Developed by Meta (Facebook)

  • Uses JavaScript and React
  • Bridges to native views
  • Large community and mature ecosystem

Pros:

  • Reuse web development skills
  • Supports third-party plugins and native modules
  • Strong developer tools (Expo, Metro, etc.)

Cons:

  • Occasional native debugging needed
  • Performance depends on architecture

Used by: Instagram, Shopify, Discord (partially)

🔗 reactnative.dev

🎨 Flutter

Developed by Google

  • Uses the Dart language
  • Fully custom rendering engine — draws everything from scratch
  • Compiles to native code (no WebView)

Pros:

  • Beautiful, consistent UIs
  • Excellent performance
  • Growing ecosystem

Cons:

  • Dart is less familiar than JS or Python
  • Larger bundle sizes
  • Some platform-specific bugs

Used by: Google Ads, Alibaba, BMW, Reflectly

🔗 flutter.dev

🖥️ .NET MAUI

From Microsoft (evolution of Xamarin.Forms)

  • Uses C# and XAML
  • Targets Android, iOS, Windows, and macOS
  • Deep integration with Visual Studio

Pros:

  • Great for C# developers
  • Share UI + business logic across platforms
  • Access to full native APIs

Cons:

  • Windows-focused dev tools
  • Smaller ecosystem than React Native or Flutter

Used by: Enterprise apps, internal tools, Microsoft ecosystem

🔗 learn.microsoft.com/dotnet/maui

🧑‍💻 Bonus Example: VS Code

Visual Studio Code is a fantastic example of a cross-platform desktop application. It runs on Windows, macOS, and Linux — and powers millions of developers’ workflows every day.

It’s built on Electron, a framework that combines Chromium and Node.js to let you create desktop apps using web technologies.

In fact, the same technology behind VS Code also powers tools like:

  • Slack (desktop)
  • Discord
  • Google Firebase Studio (in the browser — an evolution of the same architecture)

🔗 code.visualstudio.com

🤔 When Is Cross-Platform the Right Fit?

✅ Choose it if:

  • You want to move fast and support multiple platforms
  • You don’t need edge-case native APIs
  • Your team has strong web or C# experience
  • You’re building an MVP or internal tool

🚫 Avoid it if:

  • Your app needs ultra-high performance (gaming, AR/VR)
  • You need platform-specific UI patterns
  • You already have deep iOS or Android expertise

In general, cross-platform shines for most apps. Native still rules for highly customized, platform-tuned experiences.

🧪 Your Challenge

Choose one cross-platform framework and:

  • Set up a simple “Hello World” app using their quickstart guide
  • Try recreating your subscription form or habit tracker UI
  • Test it on two platforms (mobile + web, or Android + iOS)

Reflect on:

  • How easy was it to get started?
  • What felt familiar or different?
  • Could you see yourself using this for a real project?

🔗 Further Exploration

Next up: we’ll step back and explore accessibility — how to build interfaces that work for everyone, not just most people.