The most reliable approach. Google Play filters device compatibility using your AndroidManifest.xml before the user ever sees an install button.

Set minSdkVersion honestly

<uses-sdk
    android:minSdkVersion="26"
    android:targetSdkVersion="34" />

If your app genuinely requires API 26+ behaviour, declare it. Do not set a low minSdkVersion to maximise install numbers if the app will not function correctly on those versions.

Declare hardware features you actually require

<!-- Camera2 API -->
<uses-feature android:name="android.hardware.camera2" android:required="true" />

<!-- Standard camera hardware (not custom HAL) -->
<uses-feature android:name="android.hardware.camera" android:required="true" />

<!-- Gyroscope, GPS, NFC — only if truly required -->
<uses-feature android:name="android.hardware.sensor.gyroscope" android:required="true" />

Use the Play Console device catalogue

In the Play Console under Release → [Track] → Device catalogue, you can explicitly exclude specific device models — no code required. Use this when you have confirmed incompatibility with a specific SKU (e.g. catmobile_s61) and cannot resolve it at the manifest level.

When manifest filtering is insufficient — for example, when a device advertises a feature via a non-standard HAL that your code cannot actually use — check compatibility at first launch and exit cleanly.

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        if (!isDeviceCompatible()) {
            showIncompatibilityDialog()
            return  // nothing else runs
        }

        setContentView(R.layout.activity_main)
    }

    private fun isDeviceCompatible(): Boolean {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) return false

        val cameraManager = getSystemService(CAMERA_SERVICE) as CameraManager
        val hasFullCamera = cameraManager.cameraIdList.any { id ->
            val caps = cameraManager.getCameraCharacteristics(id)
                .get(CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL)
            caps == CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_FULL ||
            caps == CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_3
        }
        return hasFullCamera
    }

    private fun showIncompatibilityDialog() {
        AlertDialog.Builder(this)
            .setTitle("Device Not Supported")
            .setMessage(
                "This app requires Android 10 or later and a Camera2-compatible camera. " +
                "Your device does not meet these requirements.\n\n" +
                "No changes have been made to your device. " +
                "You can safely uninstall this app."
            )
            .setPositiveButton("Uninstall") { _, _ ->
                val intent = Intent(Intent.ACTION_DELETE).apply {
                    data = Uri.parse("package:$packageName")
                }
                startActivity(intent)
            }
            .setNegativeButton("Close") { _, _ -> finish() }
            .setCancelable(false)
            .show()
    }
}

The dialog must

• State clearly that the device is not supported
• Confirm that nothing has been changed on the device
• Offer a direct path to uninstall
• Work offline — no network access required to display
• Not proceed to initialise any services, sensors, or background workers before this check

• Do not enumerate sensors speculatively on startup
• Do not bind to hardware services in the background unless actively in use
• Release camera and sensor resources in onPause(), not onDestroy()

private val knownIncompatibleDevices = setOf(
    "catmobile:s61",  // dual-HAL camera stack, Android 9 max
)

private fun isKnownIncompatibleDevice(): Boolean {
    val fingerprint = "${Build.BRAND}:${Build.MODEL}".lowercase()
    return knownIncompatibleDevices.any { fingerprint.contains(it) }
}