diff --git a/android_app/app/src/main/AndroidManifest.xml b/android_app/app/src/main/AndroidManifest.xml
index 2405dc72..4a721b13 100644
--- a/android_app/app/src/main/AndroidManifest.xml
+++ b/android_app/app/src/main/AndroidManifest.xml
@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.health.openscale"
-    android:versionCode="9"
-    android:versionName="1.4.1" >
+    android:versionCode="10"
+    android:versionName="1.4.2" >
 
     <uses-permission android:name="android.permission.BLUETOOTH"/>
     <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
diff --git a/android_app/app/src/main/java/com/health/openscale/core/OpenScale.java b/android_app/app/src/main/java/com/health/openscale/core/OpenScale.java
index f8f17390..0340d085 100644
--- a/android_app/app/src/main/java/com/health/openscale/core/OpenScale.java
+++ b/android_app/app/src/main/java/com/health/openscale/core/OpenScale.java
@@ -35,6 +35,8 @@ import java.io.OutputStreamWriter;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
+import java.util.Map;
+import java.util.TreeMap;
 
 import static com.health.openscale.core.BluetoothCommunication.BT_MI_SCALE;
 import static com.health.openscale.core.BluetoothCommunication.BT_OPEN_SCALE;
@@ -154,15 +156,29 @@ public class OpenScale {
         return scaleDB.getDataEntry(id);
     }
 
-    public void addScaleData(ScaleData scaleData) {
-        addScaleData(scaleData.user_id, dateTimeFormat.format(scaleData.date_time).toString(), scaleData.weight, scaleData.fat,
+    public int addScaleData(ScaleData scaleData) {
+        return addScaleData(scaleData.user_id, dateTimeFormat.format(scaleData.date_time).toString(), scaleData.weight, scaleData.fat,
                 scaleData.water, scaleData.muscle, scaleData.waist, scaleData.hip, scaleData.comment);
     }
 
-	public void addScaleData(int user_id, String date_time, float weight, float fat,
+	public int addScaleData(int user_id, String date_time, float weight, float fat,
 			float water, float muscle, float waist, float hip, String comment) {
 		ScaleData scaleData = new ScaleData();
 
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+
+        if (user_id == -1) {
+            if (prefs.getBoolean("smartUserAssign", false)) {
+                user_id = getSmartUserAssignment(weight, 15.0f);
+            } else {
+                user_id = getSelectedScaleUser().id;
+            }
+
+            if (user_id == -1) {
+                return -1;
+            }
+        }
+
 		try {
             scaleData.user_id = user_id;
 			scaleData.date_time = dateTimeFormat.parse(date_time);
@@ -180,8 +196,34 @@ public class OpenScale {
 		if (scaleDB.insertEntry(scaleData)) {
             updateScaleData();
         }
+
+        return user_id;
 	}
 
+    private int getSmartUserAssignment(float weight, float range) {
+        ArrayList<ScaleUser> scaleUser = getScaleUserList();
+        Map<Float, Integer> inRangeWeights = new TreeMap<>();
+
+        for (int i = 0; i < scaleUser.size(); i++) {
+            ArrayList<ScaleData> scaleUserData = scaleDB.getScaleDataList(scaleUser.get(i).id);
+
+            if (scaleUserData.size() > 0) {
+                float lastWeight = scaleUserData.get(0).weight;
+
+                if ((lastWeight - range) <= weight && (lastWeight + range) >= weight) {
+                    inRangeWeights.put(Math.abs(lastWeight - weight), scaleUser.get(i).id);
+                }
+            }
+        }
+
+        if (inRangeWeights.size() > 0) {
+            // return the user id which is nearest to the weight (first element of the tree map)
+            return inRangeWeights.entrySet().iterator().next().getValue();
+        }
+
+        return getSelectedScaleUser().id;
+    }
+
     public void updateScaleData(long id, String date_time, float weight, float fat, float water, float muscle, float waist, float hip, String comment) {
         ScaleData scaleData = new ScaleData();
 
diff --git a/android_app/app/src/main/java/com/health/openscale/core/ScaleData.java b/android_app/app/src/main/java/com/health/openscale/core/ScaleData.java
index 086f9e68..e3f1e96a 100644
--- a/android_app/app/src/main/java/com/health/openscale/core/ScaleData.java
+++ b/android_app/app/src/main/java/com/health/openscale/core/ScaleData.java
@@ -35,12 +35,12 @@ public class ScaleData {
         id = -1;
         user_id = -1;
         date_time = new Date();
-        weight = -1.0f;
-        fat = -1.0f;
-        water = -1.0f;
-        muscle = -1.0f;
-        waist = -1.0f;
-        hip = -1.0f;
+        weight = 0.0f;
+        fat = 0.0f;
+        water = 0.0f;
+        muscle = 0.0f;
+        waist = 0.0f;
+        hip = 0.0f;
         comment = new String();
     }
 
diff --git a/android_app/app/src/main/java/com/health/openscale/gui/DataEntryActivity.java b/android_app/app/src/main/java/com/health/openscale/gui/DataEntryActivity.java
index 63a1e4bc..cdf72601 100644
--- a/android_app/app/src/main/java/com/health/openscale/gui/DataEntryActivity.java
+++ b/android_app/app/src/main/java/com/health/openscale/gui/DataEntryActivity.java
@@ -135,12 +135,12 @@ public class DataEntryActivity extends Activity {
             row.setVisibility(View.GONE);
         }
 
-        if(!prefs.getBoolean("waistEnable", true)) {
+        if(!prefs.getBoolean("waistEnable", false)) {
             TableRow row = (TableRow)findViewById(R.id.tableRowWaist);
             row.setVisibility(View.GONE);
         }
 
-        if(!prefs.getBoolean("hipEnable", true)) {
+        if(!prefs.getBoolean("hipEnable", false)) {
             TableRow row = (TableRow)findViewById(R.id.tableRowHip);
             row.setVisibility(View.GONE);
         }
@@ -258,7 +258,7 @@ public class DataEntryActivity extends Activity {
             }
         }
 
-        if (prefs.getBoolean("waistEnable", true)) {
+        if (prefs.getBoolean("waistEnable", false)) {
             if (txtWaist.getText().toString().length() == 0) {
                 txtWaist.setError(getResources().getString(R.string.error_waist_value_required));
                 validate = false;
@@ -268,7 +268,7 @@ public class DataEntryActivity extends Activity {
             }
         }
 
-        if (prefs.getBoolean("hipEnable", true)) {
+        if (prefs.getBoolean("hipEnable", false)) {
             if (txtHip.getText().toString().length() == 0) {
                 txtHip.setError(getResources().getString(R.string.error_hip_value_required));
                 validate = false;
diff --git a/android_app/app/src/main/java/com/health/openscale/gui/MainActivity.java b/android_app/app/src/main/java/com/health/openscale/gui/MainActivity.java
index 977f1f0c..f5442e44 100644
--- a/android_app/app/src/main/java/com/health/openscale/gui/MainActivity.java
+++ b/android_app/app/src/main/java/com/health/openscale/gui/MainActivity.java
@@ -17,6 +17,8 @@
 package com.health.openscale.gui;
 
 import android.bluetooth.BluetoothAdapter;
+import android.bluetooth.BluetoothManager;
+import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.content.pm.PackageManager;
@@ -143,9 +145,6 @@ public class MainActivity extends ActionBarActivity implements
 
 	@Override
 	public boolean onOptionsItemSelected(MenuItem item) {
-		// Handle action bar item clicks here. The action bar will
-		// automatically handle clicks on the Home/Up button, so long
-		// as you specify a parent activity in AndroidManifest.xml.
 		int id = item.getItemId();
 
 		if (id == R.id.action_general_settings) {
@@ -155,16 +154,7 @@ public class MainActivity extends ActionBarActivity implements
 		}
 
 		if (id == R.id.action_bluetooth_status) {
-			SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
-
-			if (BluetoothAdapter.getDefaultAdapter().isEnabled()) {
-				String deviceName = prefs.getString("btDeviceName", "MI_SCALE");
-				Toast.makeText(getApplicationContext(), getResources().getString(R.string.info_bluetooth_try_connection) + " " + deviceName, Toast.LENGTH_SHORT).show();
-				invokeSearchBluetoothDevice();
-			} else {
-				setBluetoothStatusIcon(R.drawable.bluetooth_disabled);
-				Toast.makeText(getApplicationContext(), "Bluetooth " + getResources().getString(R.string.info_is_not_enable), Toast.LENGTH_SHORT).show();
-			}
+			invokeSearchBluetoothDevice();
 			return true;
 		}
 
@@ -172,7 +162,15 @@ public class MainActivity extends ActionBarActivity implements
 	}
 
 	private void invokeSearchBluetoothDevice() {
-		if (!BluetoothAdapter.getDefaultAdapter().isEnabled()) {
+		final BluetoothManager bluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
+		BluetoothAdapter btAdapter = bluetoothManager.getAdapter();
+
+		if (btAdapter == null || !btAdapter.isEnabled()) {
+			setBluetoothStatusIcon(R.drawable.bluetooth_disabled);
+			Toast.makeText(getApplicationContext(), "Bluetooth " + getResources().getString(R.string.info_is_not_enable), Toast.LENGTH_SHORT).show();
+
+			Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
+			startActivityForResult(enableBtIntent, 1);
 			return;
 		}
 
@@ -190,6 +188,7 @@ public class MainActivity extends ActionBarActivity implements
 			}
 		}
 
+		Toast.makeText(getApplicationContext(), getResources().getString(R.string.info_bluetooth_try_connection) + " " + deviceName, Toast.LENGTH_SHORT).show();
 		setBluetoothStatusIcon(R.drawable.bluetooth_searching);
 
 		OpenScale.getInstance(getApplicationContext()).stopSearchingForBluetooth();
@@ -205,12 +204,9 @@ public class MainActivity extends ActionBarActivity implements
 					setBluetoothStatusIcon(R.drawable.bluetooth_connection_success);
 					ScaleData scaleBtData = (ScaleData) msg.obj;
 
-					// if no user id is set, use the current user id
-					if (scaleBtData.user_id == -1) {
-						scaleBtData.user_id = OpenScale.getInstance(getApplicationContext()).getSelectedScaleUser().id;
+					if (OpenScale.getInstance(getApplicationContext()).addScaleData(scaleBtData) == -1) {
+						Toast.makeText(getApplicationContext(), getResources().getString(R.string.info_no_selected_user) + "(" + getResources().getString(R.string.label_weight) + ": " + scaleBtData.weight + ")", Toast.LENGTH_SHORT).show();
 					}
-
-					OpenScale.getInstance(getApplicationContext()).addScaleData(scaleBtData);
 					break;
 				case BluetoothCommunication.BT_INIT_PROCESS:
 					setBluetoothStatusIcon(R.drawable.bluetooth_connection_success);
diff --git a/android_app/app/src/main/java/com/health/openscale/gui/OverviewFragment.java b/android_app/app/src/main/java/com/health/openscale/gui/OverviewFragment.java
index e1394b0e..25904503 100644
--- a/android_app/app/src/main/java/com/health/openscale/gui/OverviewFragment.java
+++ b/android_app/app/src/main/java/com/health/openscale/gui/OverviewFragment.java
@@ -481,7 +481,7 @@ public class OverviewFragment extends Fragment implements FragmentUpdateListener
             lines++;
         }
 
-        if(prefs.getBoolean("waistEnable", true)) {
+        if(prefs.getBoolean("waistEnable", false)) {
             info_week +=  String.format("Ø-"+getResources().getString(R.string.label_waist)+": %.1fcm <br>", weekAvgWaist);
             info_month += String.format("Ø-"+getResources().getString(R.string.label_waist)+": %.1fcm <br>", monthAvgWaist);
             lines++;
@@ -491,13 +491,13 @@ public class OverviewFragment extends Fragment implements FragmentUpdateListener
             lines++;
         }
 
-        if(prefs.getBoolean("hipEnable", true)) {
+        if(prefs.getBoolean("hipEnable", false)) {
             info_week +=  String.format("Ø-"+getResources().getString(R.string.label_hip)+": %.1fcm <br>", weekAvgHip);
             info_month += String.format("Ø-"+getResources().getString(R.string.label_hip)+": %.1fcm <br>",monthAvgHip);
             lines++;
         }
 
-        if(prefs.getBoolean("hipEnable", true) && prefs.getBoolean("waistEnable", true)) {
+        if(prefs.getBoolean("hipEnable", false) && prefs.getBoolean("waistEnable", false)) {
             info_week +=  String.format("Ø-"+getResources().getString(R.string.label_whr)+": %.2f <br>", weekAvgWHR);
             info_month += String.format("Ø-"+getResources().getString(R.string.label_whr)+": %.2f <br>", monthAvgWHR);
             lines++;
@@ -603,11 +603,11 @@ public class OverviewFragment extends Fragment implements FragmentUpdateListener
             lines.add(lineMuscle);
         }
 
-        if(prefs.getBoolean("waistEnable", true)) {
+        if(prefs.getBoolean("waistEnable", false)) {
             lines.add(lineWaist);
         }
 
-        if(prefs.getBoolean("hipEnable", true)) {
+        if(prefs.getBoolean("hipEnable", false)) {
             lines.add(lineHip);
         }
 
diff --git a/android_app/app/src/main/res/values-de/strings.xml b/android_app/app/src/main/res/values-de/strings.xml
index 17a78c42..b6c12f8c 100644
--- a/android_app/app/src/main/res/values-de/strings.xml
+++ b/android_app/app/src/main/res/values-de/strings.xml
@@ -29,7 +29,7 @@
     <string name="info_is_not_visible">ist nicht sichtbar</string>
     <string name="info_is_visible">ist sichtbar</string>
     <string name="info_is_not_available">ist nicht verfügbar</string>
-    <string name="info_no_selected_user">Kein Benutzer existiert! Bitte lege einen neuen Benutzer unter Einstellungen an</string>
+    <string name="info_no_selected_user">Kein Benutzer vorhanden. Bitte erzeugen Sie ein neuen Benutzer unter Einstellungen.</string>
     <string name="info_on_date">am</string>
     <string name="info_set_filename">Setzte Dateiname auf</string>
     <string name="info_your_fat">Dein Körperfett war</string>
@@ -104,4 +104,5 @@
     <string name="info_bluetooth_try_connection">Versuche Verbindung herzustellen zu</string>
     <string name="label_device_type">Gerätetyp</string>
     <string name="info_bluetooth_init">Initializiere Bluetooth Gerät</string>
+    <string name="label_smartUserAssign">Intelligente Benutzer Zuweisung</string>
 </resources>
\ No newline at end of file
diff --git a/android_app/app/src/main/res/values-ja/strings.xml b/android_app/app/src/main/res/values-ja/strings.xml
index 3faebbcf..63089b1c 100644
--- a/android_app/app/src/main/res/values-ja/strings.xml
+++ b/android_app/app/src/main/res/values-ja/strings.xml
@@ -104,4 +104,5 @@
     <string name="info_bluetooth_connection_successful">接続に成功しました</string>
     <string name="label_device_type">デバイスタイプ</string>
     <string name="info_bluetooth_init">Bluetooth接続を初期化する</string>
+    <string name="label_smartUserAssign">スマートユーザーのアサイン</string>
 </resources>
\ No newline at end of file
diff --git a/android_app/app/src/main/res/values/strings.xml b/android_app/app/src/main/res/values/strings.xml
index b2199234..b974de7d 100644
--- a/android_app/app/src/main/res/values/strings.xml
+++ b/android_app/app/src/main/res/values/strings.xml
@@ -30,6 +30,7 @@
     <string name="label_comment">Comment</string>
     <string name="label_whtr">Waist-to-height ratio</string>
     <string name="label_whr">Waist-hip ratio</string>
+    <string name="label_smartUserAssign">Smart User assignment</string>
 
     <string name="label_days">days</string>
     <string name="label_measures">measures</string>
@@ -100,7 +101,7 @@
     <string name="info_bluetooth_connection_error">Bluetooth has an unexpected error</string>
 
     <string name="info_enter_user_name">Enter your name</string>
-    <string name="info_no_selected_user">No user exist! Please create a new user in the settings</string>
+    <string name="info_no_selected_user">No user exists. Please create a new user in the settings.</string>
     <string name="info_no_evaluation_available">Can\'t evaluate the value</string>
 
     <string name="question_really_delete_all">Do you really want to delete all database entries?</string>
diff --git a/android_app/app/src/main/res/xml/preferences.xml b/android_app/app/src/main/res/xml/preferences.xml
index 2c8fc00c..c49dc5d8 100644
--- a/android_app/app/src/main/res/xml/preferences.xml
+++ b/android_app/app/src/main/res/xml/preferences.xml
@@ -8,6 +8,7 @@
     <CheckBoxPreference android:title="@string/label_bluetooth_enable" android:summaryOn="@string/info_is_enable" android:summaryOff="@string/info_is_not_enable" android:key="btEnable" android:defaultValue="false"/>
     <ListPreference android:title="@string/label_device_type" android:key="btDeviceTypes" android:entries="@array/btDeviceTypes" android:entryValues="@array/btDeviceTypesAlias" android:defaultValue="0"/>
     <EditTextPreference android:title="@string/label_device_name" android:key="btDeviceName" android:defaultValue="MI_SCALE" />
+    <CheckBoxPreference android:title="@string/label_smartUserAssign" android:summaryOn="@string/info_is_enable" android:summaryOff="@string/info_is_not_enable"  android:key="smartUserAssign" android:defaultValue="false"/>
 </PreferenceCategory>
 
 <PreferenceCategory android:title="@string/title_graph">
@@ -15,7 +16,6 @@
 </PreferenceCategory>
 
 <PreferenceCategory android:title="@string/title_data">
-    <CheckBoxPreference android:title="@string/label_weight" android:summaryOn="@string/info_is_enable" android:summaryOff="@string/info_is_not_enable"  android:key="weightEnable" android:defaultValue="true"/>
     <CheckBoxPreference android:title="@string/label_fat" android:summaryOn="@string/info_is_enable" android:summaryOff="@string/info_is_not_enable" android:key="fatEnable" android:defaultValue="true"/>
     <CheckBoxPreference android:title="@string/label_water" android:summaryOn="@string/info_is_enable" android:summaryOff="@string/info_is_not_enable"   android:key="waterEnable" android:defaultValue="true"/>
     <CheckBoxPreference android:title="@string/label_muscle" android:summaryOn="@string/info_is_enable" android:summaryOff="@string/info_is_not_enable"  android:key="muscleEnable" android:defaultValue="true"/>