App icon: winged-bubble adaptive icon (Android) + window/jpackage icon (desktop); concept art in app/icons/

app/desktopApp/build.gradle.kts

@@ -75,6 +75,7 @@ tasks.register<Exec>("jpackage") {
         "--input", inputDir.absolutePath,
         "--main-jar", "desktopApp-all.jar",
         "--main-class", "iris.desktop.MainKt",
+        "--icon", file("src/main/resources/icon.png").absolutePath,
         "--dest", destDir.absolutePath,
         "--java-options", "-Xmx1g",
     )

app/desktopApp/src/main/kotlin/iris/desktop/Main.kt

@@ -21,6 +21,7 @@ import iris.platform.DesktopBridge
 import iris.platform.DesktopSecureStore
 import java.awt.Color
 import java.awt.Graphics2D
+import javax.imageio.ImageIO
 import java.awt.RenderingHints
 import java.awt.SystemTray
 import java.awt.event.WindowEvent
@@ -45,6 +46,10 @@ import kotlinx.serialization.json.jsonPrimitive
  */
 private val windowJson = File(System.getProperty("user.home"), ".iris/window.json")
 
+// Window/taskbar icon (src/main/resources/icon.png).
+private class IrisDesktop
+private val windowIcon = ImageIO.read(IrisDesktop::class.java.getResource("/icon.png")!!).toComposeImageBitmap()
+
 // Tray icon colors (ARGB). .toInt(): the literals exceed the Int range.
 private const val TRAY_OFFLINE = 0xFF9E9E9E.toInt()
 private const val TRAY_CONNECTING = 0xFFFFC107.toInt()
@@ -107,6 +112,7 @@ fun main() {
         }
 
         Window(
+            icon = BitmapPainter(windowIcon),
             onCloseRequest = {
                 if (closeToTray.get()) {
                     composeWindow?.isVisible = false