diff --git a/src-tauri/gen/android/app/src/main/java/dev/baldav/app/MainActivity.kt b/src-tauri/gen/android/app/src/main/java/dev/baldav/app/MainActivity.kt
new file mode 100644
index 0000000..0cf3364
--- /dev/null
+++ b/src-tauri/gen/android/app/src/main/java/dev/baldav/app/MainActivity.kt
@@ -0,0 +1,151 @@
+package dev.baldav.app
+
+import android.app.Activity
+import android.content.Intent
+import android.net.Uri
+import android.os.Build
+import android.os.Bundle
+import android.os.FileObserver
+import android.util.Log
+import androidx.activity.enableEdgeToEdge
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.core.view.ViewCompat
+import androidx.core.view.WindowInsetsCompat
+import java.io.File
+
+class MainActivity : TauriActivity() {
+  private var commandObserver: FileObserver? = null
+  private var pendingSaveContent: String? = null
+
+  private val saveFileLauncher = registerForActivityResult(
+    ActivityResultContracts.CreateDocument("application/gpx+xml")
+  ) { uri: Uri? ->
+    if (uri != null && pendingSaveContent != null) {
+      try {
+        contentResolver.openOutputStream(uri)?.use { it.write(pendingSaveContent!!.toByteArray()) }
+        Log.d("BalDav", "File saved to $uri")
+      } catch (e: Exception) {
+        Log.e("BalDav", "Failed to save file", e)
+      }
+    }
+    pendingSaveContent = null
+  }
+
+  override fun onCreate(savedInstanceState: Bundle?) {
+    enableEdgeToEdge()
+    super.onCreate(savedInstanceState)
+
+    // Rust app_data_dir() on Android = app's root data dir (filesDir.parentFile)
+    val appDataDir = filesDir.parentFile ?: filesDir
+    Log.d("BalDav", "App data dir: ${appDataDir.absolutePath}")
+
+    // Create command file if not exists (FileObserver needs it)
+    val cmdFile = File(appDataDir, "gps_command.txt")
+    if (!cmdFile.exists()) cmdFile.createNewFile()
+
+    setupCommandWatcher(appDataDir)
+    processGpsCommand(appDataDir)
+    Log.d("BalDav", "Command watcher started on ${appDataDir.absolutePath}")
+
+    // Copy seed DB from assets to filesDir (Rust can't read Android assets directly).
+    // Always overwrite — APK updates may contain a newer seed DB.
+    try {
+      val seedDest = File(filesDir, "products_seed.db")
+      val assetSize = assets.open("frontend/data/products_seed.db").use { it.available().toLong() }
+      if (!seedDest.exists() || seedDest.length() != assetSize) {
+        assets.open("frontend/data/products_seed.db").use { input ->
+          seedDest.outputStream().use { output ->
+            input.copyTo(output)
+          }
+        }
+        Log.d("BalDav", "Seed DB copied to ${seedDest.absolutePath} (${seedDest.length()} bytes)")
+      }
+    } catch (e: Exception) {
+      Log.e("BalDav", "Failed to copy seed DB", e)
+    }
+
+    val decorView = window.decorView
+    ViewCompat.setOnApplyWindowInsetsListener(decorView) { view, insets ->
+      val statusBar = insets.getInsets(WindowInsetsCompat.Type.statusBars())
+      val navBar = insets.getInsets(WindowInsetsCompat.Type.navigationBars())
+      val density = resources.displayMetrics.density
+      val top = (statusBar.top / density).toInt()
+      val bottom = (navBar.bottom / density).toInt()
+      val left = (navBar.left / density).toInt()
+      val right = (navBar.right / density).toInt()
+      try {
+        val insetsFile = File(filesDir, "safe_insets.json")
+        insetsFile.writeText("""{"top":$top,"bottom":$bottom,"left":$left,"right":$right}""")
+        Log.d("BalDav", "Safe insets: top=$top bottom=$bottom left=$left right=$right")
+      } catch (e: Exception) {
+        Log.e("BalDav", "Failed to write safe insets", e)
+      }
+      ViewCompat.onApplyWindowInsets(view, insets)
+    }
+  }
+
+  private fun setupCommandWatcher(appDataDir: File) {
+    commandObserver = object : FileObserver(appDataDir.absolutePath, CREATE or CLOSE_WRITE or MODIFY or MOVED_TO) {
+      override fun onEvent(event: Int, path: String?) {
+        if (path == "gps_command.txt") {
+          Log.d("BalDav", "Command file event: $event")
+          runOnUiThread { processGpsCommand(appDataDir) }
+        }
+      }
+    }
+    commandObserver?.startWatching()
+    Log.d("BalDav", "FileObserver started on ${appDataDir.absolutePath}")
+  }
+
+  private fun processGpsCommand(appDataDir: File) {
+    val cmdFile = File(appDataDir, "gps_command.txt")
+    if (!cmdFile.exists()) return
+    val cmd = cmdFile.readText().trim()
+    if (cmd.isEmpty()) return
+    cmdFile.writeText("")  // Clear but don't delete (FileObserver needs the file)
+
+    Log.d("BalDav", "Processing GPS command: $cmd")
+
+    when {
+      cmd.startsWith("start") -> {
+        val parts = cmd.split(":")
+        val minSpeed = parts.getOrNull(1)?.toFloatOrNull() ?: 0.42f
+        val maxAcc = parts.getOrNull(2)?.toFloatOrNull() ?: 20f
+        val minDist = parts.getOrNull(3)?.toFloatOrNull() ?: 1f
+        Log.d("BalDav", "Starting GPS service: speed=$minSpeed acc=$maxAcc dist=$minDist")
+        val intent = Intent(this, GpsRecorderService::class.java).apply {
+          putExtra(GpsRecorderService.EXTRA_MIN_SPEED, minSpeed)
+          putExtra(GpsRecorderService.EXTRA_MAX_ACC, maxAcc)
+          putExtra(GpsRecorderService.EXTRA_MIN_DIST, minDist)
+        }
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+          startForegroundService(intent)
+        } else {
+          startService(intent)
+        }
+      }
+      cmd == "stop" -> {
+        Log.d("BalDav", "Stopping GPS service")
+        val intent = Intent(this, GpsRecorderService::class.java)
+        intent.action = GpsRecorderService.ACTION_STOP
+        startService(intent)
+      }
+      cmd.startsWith("save:") -> {
+        // save:filename.gpx — read content from save_content.txt, show SAF picker
+        val filename = cmd.substringAfter("save:")
+        val contentFile = File(appDataDir, "save_content.txt")
+        if (contentFile.exists()) {
+          pendingSaveContent = contentFile.readText()
+          contentFile.delete()
+          Log.d("BalDav", "Opening save dialog for $filename (${pendingSaveContent?.length} bytes)")
+          saveFileLauncher.launch(filename)
+        }
+      }
+    }
+  }
+
+  override fun onDestroy() {
+    commandObserver?.stopWatching()
+    super.onDestroy()
+  }
+}