If you want one codebase that works on both Android and iOS, you should use a cross-platform framework instead of writing separate code in Java/Kotlin (Android) and Swift/Objective-C (iOS).
Here are the best options (2025 reality):
Best Languages / Frameworks for Android + iOS
1. Flutter (Dart)
- Language: Dart
- Why:
- Single codebase → runs natively on Android + iOS.
- Great performance (compiled to native ARM code).
- Huge community, backed by Google.
- Perfect for apps with modern UIs.
- Use case: Startup apps, dashboards, chat apps, fintech, e-commerce.
2. React Native (JavaScript / TypeScript)
- Language: JavaScript (or TypeScript, which is recommended).
- Why:
- Backed by Meta (Facebook).
- Can reuse existing web development skills.
- Strong ecosystem (Expo, libraries).
- Use case: Social apps, MVPs, apps that already have a web React frontend.
3. Kotlin Multiplatform (Kotlin)
- Language: Kotlin
- Why:
- Share business logic across Android + iOS, but still write native UI for each.
- Good if you already use Kotlin for Android.
- Use case: Enterprise apps, where performance and platform-specific UI matter.
4. .NET MAUI (C#)
- Language: C#
- Why:
- Successor of Xamarin.
- Backed by Microsoft.
- Good if your company already uses .NET stack.
- Use case: Internal business apps, enterprise apps.
My Recommendation (2025):
- If you want modern UI + speed + one team, one codebase → go with Flutter (Dart).
- If you have web dev background → React Native (JS/TS).
- If you’re an Android developer expanding to iOS → Kotlin Multiplatform.
