diff --git a/app/src/main/java/org/solovyev/android/calculator/CalculatorActivity.java b/app/src/main/java/org/solovyev/android/calculator/CalculatorActivity.java
index 1ee5c6f2..4f9563ac 100644
--- a/app/src/main/java/org/solovyev/android/calculator/CalculatorActivity.java
+++ b/app/src/main/java/org/solovyev/android/calculator/CalculatorActivity.java
@@ -38,9 +38,7 @@ import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
 import android.widget.FrameLayout;
-import butterknife.Bind;
-import jscl.AngleUnit;
-import jscl.NumeralBase;
+
 import org.solovyev.android.calculator.converter.ConverterFragment;
 import org.solovyev.android.calculator.history.History;
 import org.solovyev.android.calculator.keyboard.PartialKeyboardUi;
@@ -50,6 +48,10 @@ import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
+import butterknife.Bind;
+import jscl.AngleUnit;
+import jscl.NumeralBase;
+
 public class CalculatorActivity extends BaseActivity implements View.OnClickListener {
 
     @Nonnull
@@ -212,7 +214,7 @@ public class CalculatorActivity extends BaseActivity implements View.OnClickList
             final Menu menu = popup.getMenu();
             final MenuItem menuItem = menu.findItem(R.id.menu_angle_units);
             final AngleUnit angles = Engine.Preferences.angleUnit.getPreference(preferences);
-            menuItem.setTitle(makeTitle(R.string.cpp_angles, getAngleUnitsName(angles)));
+            menuItem.setTitle(makeTitle(R.string.cpp_angles, Engine.Preferences.angleUnitName(angles)));
         }
 
         private void updateNumeralBase() {
@@ -222,37 +224,7 @@ public class CalculatorActivity extends BaseActivity implements View.OnClickList
             final Menu menu = popup.getMenu();
             final MenuItem menuItem = menu.findItem(R.id.menu_numeral_base);
             final NumeralBase numeralBase = Engine.Preferences.numeralBase.getPreference(preferences);
-            menuItem.setTitle(makeTitle(R.string.cpp_radix, getNumeralBaseName(numeralBase)));
-        }
-
-        @StringRes
-        private int getAngleUnitsName(AngleUnit angleUnit) {
-            switch (angleUnit) {
-                case deg:
-                    return R.string.p_deg;
-                case rad:
-                    return R.string.p_rad;
-                case grad:
-                    return R.string.p_grad;
-                case turns:
-                    return R.string.p_turns;
-            }
-            return 0;
-        }
-
-        @StringRes
-        private int getNumeralBaseName(NumeralBase numeralBase) {
-            switch (numeralBase) {
-                case bin:
-                    return R.string.p_bin;
-                case oct:
-                    return R.string.p_oct;
-                case dec:
-                    return R.string.p_dec;
-                case hex:
-                    return R.string.p_hex;
-            }
-            return 0;
+            menuItem.setTitle(makeTitle(R.string.cpp_radix, Engine.Preferences.numeralBaseName(numeralBase)));
         }
 
         @Override
diff --git a/app/src/main/java/org/solovyev/android/calculator/Engine.java b/app/src/main/java/org/solovyev/android/calculator/Engine.java
index 42c12a92..9cf14e82 100644
--- a/app/src/main/java/org/solovyev/android/calculator/Engine.java
+++ b/app/src/main/java/org/solovyev/android/calculator/Engine.java
@@ -335,6 +335,36 @@ public class Engine implements SharedPreferences.OnSharedPreferenceChangeListene
             return Collections.unmodifiableList(preferenceKeys);
         }
 
+        @StringRes
+        public static int angleUnitName(AngleUnit angleUnit) {
+            switch (angleUnit) {
+                case deg:
+                    return R.string.p_deg;
+                case rad:
+                    return R.string.p_rad;
+                case grad:
+                    return R.string.p_grad;
+                case turns:
+                    return R.string.p_turns;
+            }
+            return 0;
+        }
+
+        @StringRes
+        public static int numeralBaseName(NumeralBase numeralBase) {
+            switch (numeralBase) {
+                case bin:
+                    return R.string.p_bin;
+                case oct:
+                    return R.string.p_oct;
+                case dec:
+                    return R.string.p_dec;
+                case hex:
+                    return R.string.p_hex;
+            }
+            return 0;
+        }
+
         public static class Output {
             public static final StringPreference<Integer> precision = StringPreference.ofTypedValue("engine.output.precision", "5", NumberMapper.of(Integer.class));
             public static final StringPreference<Notation> notation = StringPreference.ofEnum("engine.output.notation", Notation.dec, Notation.class);
diff --git a/app/src/main/java/org/solovyev/android/calculator/preferences/PreferencesFragment.java b/app/src/main/java/org/solovyev/android/calculator/preferences/PreferencesFragment.java
index d46c5751..ee950341 100644
--- a/app/src/main/java/org/solovyev/android/calculator/preferences/PreferencesFragment.java
+++ b/app/src/main/java/org/solovyev/android/calculator/preferences/PreferencesFragment.java
@@ -11,9 +11,10 @@ import android.support.v4.app.FragmentActivity;
 import android.util.SparseArray;
 import android.view.View;
 import android.widget.ListView;
+
 import com.squareup.otto.Bus;
 import com.squareup.otto.Subscribe;
-import jscl.JsclMathEngine;
+
 import org.solovyev.android.calculator.AdView;
 import org.solovyev.android.calculator.Engine;
 import org.solovyev.android.calculator.Preferences;
@@ -29,13 +30,20 @@ import org.solovyev.android.prefs.StringPreference;
 import org.solovyev.android.wizard.Wizards;
 import org.solovyev.common.text.CharacterMapper;
 
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-import javax.inject.Inject;
 import java.util.Arrays;
 import java.util.List;
 
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import javax.inject.Inject;
+
+import jscl.AngleUnit;
+import jscl.JsclMathEngine;
+import jscl.NumeralBase;
+
 import static org.solovyev.android.calculator.App.cast;
+import static org.solovyev.android.calculator.Engine.Preferences.angleUnitName;
+import static org.solovyev.android.calculator.Engine.Preferences.numeralBaseName;
 import static org.solovyev.android.calculator.wizard.CalculatorWizards.DEFAULT_WIZARD_FLOW;
 import static org.solovyev.android.wizard.WizardUi.startWizard;
 
@@ -117,6 +125,9 @@ public class PreferencesFragment extends org.solovyev.android.material.preferenc
                     }
                 });
             }
+            prepareModePreference();
+            prepareAnglesPreference();
+            prepareRadixPreference();
         } else if (preference == R.xml.preferences_number_format) {
             prepareListPreference(Engine.Preferences.Output.notation, Engine.Notation.class);
             preparePrecisionPreference();
@@ -125,7 +136,6 @@ public class PreferencesFragment extends org.solovyev.android.material.preferenc
         }
 
         prepareLanguagePreference(preference);
-        prepareLayoutPreference(preference);
         prepareThemePreference(preference);
 
         getCheckout().whenReady(new Checkout.ListenerAdapter() {
@@ -217,16 +227,37 @@ public class PreferencesFragment extends org.solovyev.android.material.preferenc
         });
     }
 
-    private void prepareLayoutPreference(int preference) {
-        if (preference != R.xml.preferences_appearance) {
-            return;
-        }
-        final ListPreference layout = (ListPreference) preferenceManager.findPreference(Preferences.Gui.mode.getKey());
-        layout.setSummary(Preferences.Gui.getMode(preferences).name);
-        layout.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
+    private void prepareModePreference() {
+        final ListPreference mode = (ListPreference) preferenceManager.findPreference(Preferences.Gui.mode.getKey());
+        mode.setSummary(Preferences.Gui.getMode(preferences).name);
+        mode.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
             @Override
             public boolean onPreferenceChange(Preference preference, Object newValue) {
-                layout.setSummary(Preferences.Gui.Mode.valueOf((String) newValue).name);
+                mode.setSummary(Preferences.Gui.Mode.valueOf((String) newValue).name);
+                return true;
+            }
+        });
+    }
+
+    private void prepareAnglesPreference() {
+        final ListPreference angles = (ListPreference) preferenceManager.findPreference(Engine.Preferences.angleUnit.getKey());
+        angles.setSummary(angleUnitName(Engine.Preferences.angleUnit.getPreference(preferences)));
+        angles.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
+            @Override
+            public boolean onPreferenceChange(Preference preference, Object newValue) {
+                angles.setSummary(angleUnitName(AngleUnit.valueOf((String) newValue)));
+                return true;
+            }
+        });
+    }
+
+    private void prepareRadixPreference() {
+        final ListPreference radix = (ListPreference) preferenceManager.findPreference(Engine.Preferences.numeralBase.getKey());
+        radix.setSummary(numeralBaseName(Engine.Preferences.numeralBase.getPreference(preferences)));
+        radix.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
+            @Override
+            public boolean onPreferenceChange(Preference preference, Object newValue) {
+                radix.setSummary(numeralBaseName(NumeralBase.valueOf((String) newValue)));
                 return true;
             }
         });
diff --git a/app/src/main/res/xml/preferences.xml b/app/src/main/res/xml/preferences.xml
index fdebae46..83a43637 100644
--- a/app/src/main/res/xml/preferences.xml
+++ b/app/src/main/res/xml/preferences.xml
@@ -31,28 +31,67 @@
         a:summary="@string/c_calc_ad_free_summary"
         a:title="@string/c_calc_ad_free_title" />
 
-    <Preference
-        a:key="restart_wizard"
-        a:title="@string/cpp_restart_wizard" />
+    <PreferenceCategory
+        a:key="category-basic"
+        a:title="Basic">
 
-    <Preference
-        a:key="screen-number-format"
-        a:title="Number format" />
+        <ListPreference
+            a:entries="@array/p_layout_names"
+            a:entryValues="@array/p_layout_values"
+            a:key="gui.mode"
+            a:title="@string/cpp_mode" />
 
-    <Preference
-        a:key="screen-calculations"
-        a:title="@string/c_prefs_calculations_category" />
-    <Preference
-        a:key="screen-appearance"
-        a:title="@string/c_prefs_appearance_category" />
-    <Preference
-        a:key="screen-other"
-        a:title="@string/c_prefs_other_category" />
-    <Preference
-        a:key="screen-onscreen"
-        a:title="@string/prefs_onscreen_title" />
-    <Preference
-        a:key="screen-widget"
-        a:title="@string/prefs_widget_title" />
+        <ListPreference
+            a:entries="@array/p_angle_units_names"
+            a:entryValues="@array/p_angle_units"
+            a:key="engine.angleUnit"
+            a:title="@string/cpp_angles" />
+
+        <ListPreference
+            a:entries="@array/p_numeral_bases_names"
+            a:entryValues="@array/p_numeral_bases"
+            a:key="engine.numeralBase"
+            a:title="@string/cpp_radix" />
+
+        <Preference
+            a:key="screen-number-format"
+            a:title="Number format" />
+    </PreferenceCategory>
+
+    <PreferenceCategory
+        a:key="category-advanced"
+        a:title="Advanced">
+
+        <Preference
+            a:key="screen-calculations"
+            a:title="@string/c_prefs_calculations_category" />
+        <Preference
+            a:key="screen-appearance"
+            a:title="@string/c_prefs_appearance_category" />
+        <Preference
+            a:key="screen-other"
+            a:title="@string/c_prefs_other_category" />
+        <Preference
+            a:key="screen-onscreen"
+            a:title="@string/prefs_onscreen_title" />
+        <Preference
+            a:key="screen-widget"
+            a:title="@string/prefs_widget_title" />
+
+    </PreferenceCategory>
+
+    <PreferenceCategory
+        a:key="category-help"
+        a:title="Help">
+
+        <Preference
+            a:key="restart_wizard"
+            a:title="@string/cpp_restart_wizard" />
+
+        <Preference
+            a:key="prefs.reportBug"
+            a:title="Report a problem" />
+
+    </PreferenceCategory>
 
 </PreferenceScreen>
\ No newline at end of file
diff --git a/app/src/main/res/xml/preferences_appearance.xml b/app/src/main/res/xml/preferences_appearance.xml
index 687d40cf..b5781f59 100644
--- a/app/src/main/res/xml/preferences_appearance.xml
+++ b/app/src/main/res/xml/preferences_appearance.xml
@@ -38,12 +38,6 @@
         a:key="gui.theme"
         a:title="@string/cpp_theme" />
 
-    <ListPreference
-        a:entries="@array/p_layout_names"
-        a:entryValues="@array/p_layout_values"
-        a:key="gui.mode"
-        a:title="@string/cpp_mode" />
-
     <android.preference.CheckBoxPreference
         a:defaultValue="true"
         a:key="gui.rotateScreen"
diff --git a/app/src/main/res/xml/preferences_calculations.xml b/app/src/main/res/xml/preferences_calculations.xml
index 3db7afa5..2764acc0 100644
--- a/app/src/main/res/xml/preferences_calculations.xml
+++ b/app/src/main/res/xml/preferences_calculations.xml
@@ -24,20 +24,6 @@
 
 <PreferenceScreen xmlns:a="http://schemas.android.com/apk/res/android">
 
-    <ListPreference
-        a:entries="@array/p_angle_units_names"
-        a:entryValues="@array/p_angle_units"
-        a:key="engine.angleUnit"
-        a:summary="@string/c_angle_units_summary"
-        a:title="@string/c_calc_angle_units" />
-
-    <ListPreference
-        a:entries="@array/p_numeral_bases_names"
-        a:entryValues="@array/p_numeral_bases"
-        a:key="engine.numeralBase"
-        a:summary="@string/c_numeral_bases_summary"
-        a:title="@string/c_calc_numeral_bases" />
-
     <android.preference.CheckBoxPreference
         a:key="calculations_calculate_on_fly"
         a:summary="@string/p_calculations_calculate_on_fly_summary"