composeApp/
├── src/
│   ├── commonMain/        ← shared Compose code (most of the app)
│   │   └── kotlin/
│   ├── androidMain/       ← Android-specific (uses Activity, Context)
│   ├── iosMain/           ← iOS-specific (uses UIKit/UIView interop)
│   ├── desktopMain/       ← JVM desktop (uses java.awt/swing if needed)
│   └── wasmJsMain/        ← Wasm web target
├── build.gradle.kts
iosApp/                    ← Xcode project consuming the generated framework
androidApp/                ← Android Application module (often merged into composeApp)

// commonMain
expect fun openShareSheet(text: String)

// androidMain
actual fun openShareSheet(text: String) {
    val intent = Intent(Intent.ACTION_SEND).apply {
        type = "text/plain"
        putExtra(Intent.EXTRA_TEXT, text)
    }
    context.startActivity(Intent.createChooser(intent, null))
}

// iosMain
actual fun openShareSheet(text: String) {
    val activityVC = UIActivityViewController(
        activityItems = listOf(text),
        applicationActivities = null
    )
    UIApplication.sharedApplication.keyWindow
        ?.rootViewController
        ?.presentViewController(activityVC, true, null)
}

// commonMain
@Composable
expect fun PlatformBlur(modifier: Modifier = Modifier, content: @Composable () -> Unit)

// androidMain (uses RuntimeShader on Android 13+)
@Composable
actual fun PlatformBlur(modifier: Modifier, content: @Composable () -> Unit) {
    Box(modifier.graphicsLayer { renderEffect = blurEffect }) { content() }
}

// iosMain (uses UIVisualEffectView via UIKitView)
@Composable
actual fun PlatformBlur(modifier: Modifier, content: @Composable () -> Unit) {
    Box(modifier) {
        UIKitView(
            factory = { UIVisualEffectView(effect = UIBlurEffect.systemMaterial()) },
            modifier = Modifier.matchParentSize()
        )
        content()
    }
}

val density = LocalDensity.current
val pxValue = with(density) { 16.dp.toPx() }

composeApp/src/commonMain/composeResources/
├── font/
│   ├── Inter-Regular.ttf
│   └── Inter-Bold.ttf
├── drawable/
│   └── logo.svg
└── values/
    ├── strings.xml          ← default locale
    └── strings.fr.xml       ← French overrides

import myproject.composeapp.generated.resources.Inter_Regular
import myproject.composeapp.generated.resources.Inter_Bold
import myproject.composeapp.generated.resources.Res

val InterFamily = FontFamily(
    Font(Res.font.Inter_Regular, FontWeight.Normal),
    Font(Res.font.Inter_Bold, FontWeight.Bold),
)

Text("Hello", fontFamily = InterFamily)

// iosMain/kotlin/main.ios.kt
fun MainViewController(): UIViewController = ComposeUIViewController {
    AppContent()  // commonMain composable
}

// iOS app target
import SwiftUI
import ComposeApp  // KMP-generated framework

struct ComposeContent: UIViewControllerRepresentable {
    func makeUIViewController(context: Context) -> UIViewController {
        Main_iosKt.MainViewController()
    }
    func updateUIViewController(_ uiViewController: UIViewController, context: Context) {}
}

struct ContentView: View {
    var body: some View { ComposeContent().ignoresSafeArea() }
}

// androidApp/src/main/kotlin/MainActivity.kt
class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            AppContent()  // commonMain composable
        }
    }
}

// iosMain
UIKitView(
    factory = {
        UISwitch().apply {
            addTarget(target, action = NSSelectorFromString("onToggle:"), forControlEvents = UIControlEventValueChanged)
        }
    },
    modifier = Modifier.size(48.dp, 32.dp)
)