CodenameOne

Codename One compiles Java or Kotlin into native mobile binaries for iOS and Android from a single codebase, without learning Swift or platform-specific languages. Not a webview wrapper. Actual native compilation. Write once in Java/Kotlin, build to iOS (via ParparVM or iKVM), Android (native), web (via JavaScript transpilation), and desktop. The UI toolkit is custom, not native widgets, but rendered to look native. Includes a visual designer, simulator, and build cloud.

The free tier lets you build and test locally. The build cloud, which compiles your iOS builds without needing a Mac, starts at $19/month (Basic). Professional is $99/month with additional features. Enterprise pricing available.

Solo developers learning Java who want mobile: the free tier gets you started, but you'll need the $19/month plan for iOS builds unless you have a Mac with Xcode. Small teams: $99/month Professional for the full toolchain. Larger teams: evaluate against Flutter or React Native first.

The catch: the community is small for a cross-platform framework. StackOverflow answers are sparse, and if the company behind it stops, you're stuck with a niche framework and no ecosystem. Flutter and React Native have massive communities. Codename One's Java angle is its differentiator, but it's also its limitation. The mobile world moved to Dart and JavaScript/TypeScript.