diff --git a/android-app/src/main/java/org/solovyev/android/calculator/drag/DirectionDragButton.java b/android-app/src/main/java/org/solovyev/android/calculator/drag/DirectionDragButton.java
index 5e0a5581..d2852340 100644
--- a/android-app/src/main/java/org/solovyev/android/calculator/drag/DirectionDragButton.java
+++ b/android-app/src/main/java/org/solovyev/android/calculator/drag/DirectionDragButton.java
@@ -28,6 +28,7 @@ import android.graphics.Canvas;
 import android.graphics.Color;
 import android.graphics.Paint;
 import android.text.TextPaint;
+import android.text.TextUtils;
 import android.util.AttributeSet;
 import org.solovyev.common.math.Point2d;
 import org.solovyev.common.text.NumberParser;
@@ -117,7 +118,7 @@ public class DirectionDragButton extends DragButton {
 		}
 	}
 
-	protected static enum GuiDragDirection {
+	public static enum GuiDragDirection {
 		up(DragDirection.up, 0) {
 			@Override
 			public int getAttributeId() {
@@ -240,7 +241,7 @@ public class DirectionDragButton extends DragButton {
 	}
 
 	@Nonnull
-	private final Map<GuiDragDirection, DirectionTextData> textDataMap = new EnumMap<GuiDragDirection, DirectionTextData>(GuiDragDirection.class);
+	private final Map<GuiDragDirection, DirectionTextData> textDataMap = new EnumMap<>(GuiDragDirection.class);
 
 	@Nonnull
 	protected String directionTextScale = DEFAULT_DIRECTION_TEXT_SCALE;
@@ -312,6 +313,7 @@ public class DirectionDragButton extends DragButton {
 				initDirectionTextPaint(basePaint, textData);
 				textData.position = textData.direction.getTextPosition(textData.paint, basePaint, textData.text, getText(), getWidth(), getHeight());
 			}
+			invalidate();
 		}
 	}
 
@@ -361,9 +363,20 @@ public class DirectionDragButton extends DragButton {
 		}
 	}
 
+	public void setText(@Nullable String text, @Nonnull GuiDragDirection direction) {
+		if (!TextUtils.isEmpty(text)) {
+			final DirectionTextData data = new DirectionTextData(direction, text);
+			initDirectionTextPaint(getPaint(), data);
+			textDataMap.put(direction, data);
+		} else {
+			textDataMap.remove(direction);
+		}
+		measureText();
+	}
+
 	@Nullable
 	private String getText(@Nonnull GuiDragDirection direction) {
-		DirectionTextData td = this.textDataMap.get(direction);
+		DirectionTextData td = textDataMap.get(direction);
 		if (td == null) {
 			return null;
 		} else {
diff --git a/android-app/src/main/java/org/solovyev/android/calculator/wizard/ChooseModeWizardStep.java b/android-app/src/main/java/org/solovyev/android/calculator/wizard/ChooseModeWizardStep.java
index 2a72d693..6b4b0ebb 100644
--- a/android-app/src/main/java/org/solovyev/android/calculator/wizard/ChooseModeWizardStep.java
+++ b/android-app/src/main/java/org/solovyev/android/calculator/wizard/ChooseModeWizardStep.java
@@ -29,6 +29,7 @@ import android.widget.Spinner;
 import android.widget.TextView;
 import org.solovyev.android.calculator.Preferences;
 import org.solovyev.android.calculator.R;
+import org.solovyev.android.calculator.drag.DirectionDragButton;
 
 import javax.annotation.Nonnull;
 
@@ -42,6 +43,7 @@ import static org.solovyev.android.calculator.wizard.CalculatorMode.*;
  */
 public class ChooseModeWizardStep extends WizardFragment implements AdapterView.OnItemSelectedListener {
 
+	private DirectionDragButton button;
 	private TextView description;
 
 	@Override
@@ -59,12 +61,23 @@ public class ChooseModeWizardStep extends WizardFragment implements AdapterView.
 		spinner.setSelection(mode == simple ? 0 : 1);
 		spinner.setOnItemSelectedListener(this);
 
+		button = (DirectionDragButton) root.findViewById(R.id.wizard_mode_button);
 		description = (TextView) root.findViewById(R.id.wizard_mode_description);
 		updateDescription(mode);
 	}
 
 	private void updateDescription(@Nonnull CalculatorMode mode) {
-		description.setText(mode == simple ? R.string.cpp_wizard_mode_simple_description : R.string.cpp_wizard_mode_engineer_description);
+		boolean simple = mode == CalculatorMode.simple;
+		description.setText(simple ? R.string.cpp_wizard_mode_simple_description : R.string.cpp_wizard_mode_engineer_description);
+		if (simple) {
+			button.setText("", DirectionDragButton.GuiDragDirection.up);
+			button.setText("", DirectionDragButton.GuiDragDirection.down);
+			button.setText("", DirectionDragButton.GuiDragDirection.left);
+		} else {
+			button.setText("sin", DirectionDragButton.GuiDragDirection.up);
+			button.setText("ln", DirectionDragButton.GuiDragDirection.down);
+			button.setText("i", DirectionDragButton.GuiDragDirection.left);
+		}
 	}
 
 	@Override
diff --git a/android-app/src/main/res/layout/cpp_wizard_step_choose_mode.xml b/android-app/src/main/res/layout/cpp_wizard_step_choose_mode.xml
index bd73451a..203ea75c 100644
--- a/android-app/src/main/res/layout/cpp_wizard_step_choose_mode.xml
+++ b/android-app/src/main/res/layout/cpp_wizard_step_choose_mode.xml
@@ -33,18 +33,43 @@
 		a:layout_height="wrap_content"
 		a:textAppearance="@android:style/TextAppearance.Large"
 		style="@style/WizardLabel"
-		a:text="@string/cpp_wizard_mode_title"/>
+		a:layout_marginBottom="20dp"
+		a:text="@string/cpp_wizard_mode_title" />
 
 	<Spinner
 		a:id="@+id/wizard_mode_spinner"
 		a:layout_width="wrap_content"
 		a:layout_height="wrap_content"
-		style="@style/WizardLabel"/>
+		a:layout_marginBottom="20dp"
+		style="@style/WizardLabel" />
 
-	<TextView
-		a:id="@+id/wizard_mode_description"
+	<LinearLayout
 		a:layout_width="wrap_content"
 		a:layout_height="wrap_content"
-		style="@style/WizardLabel.Last"/>
+		a:orientation="vertical"
+		a:gravity="center_horizontal|top">
+
+		<FrameLayout
+			a:layout_width="wrap_content"
+			a:layout_height="wrap_content"
+			a:padding="3dp"
+			a:layout_marginBottom="10dp"
+			a:background="?attr/cpp_main_bg">
+
+			<org.solovyev.android.calculator.drag.DirectionDragButton xmlns:c="http://schemas.android.com/apk/res-auto"
+				a:id="@+id/wizard_mode_button"
+				a:text="7"
+				c:directionTextScale="0.5"
+				a:layout_width="100dp"
+				a:layout_height="100dp"
+				style="?attr/cpp_button_style_digit" />
+		</FrameLayout>
+
+		<TextView
+			a:id="@+id/wizard_mode_description"
+			a:layout_width="wrap_content"
+			a:layout_height="wrap_content"
+			style="@style/WizardLabel.Last" />
+	</LinearLayout>
 
 </LinearLayout>
diff --git a/android-app/src/main/res/values/theme.xml b/android-app/src/main/res/values/theme.xml
index 398e3719..b1a0678d 100644
--- a/android-app/src/main/res/values/theme.xml
+++ b/android-app/src/main/res/values/theme.xml
@@ -97,7 +97,7 @@
 		<item name="android:background">@color/cpp_metro_button_light</item>
 	</style>
 
-	<style name="Cpp.Theme.Wizard.Light" parent="Cpp.Theme.Light">
+	<style name="Cpp.Theme.Wizard" parent="Cpp.Theme.Material">
 		<item name="android:windowBackground">@color/cpp_wizard_bg</item>
 		<item name="android:colorEdgeEffect">@color/cpp_wizard_overscroll</item>
 		<item name="colorAccent">@color/cpp_wizard_primary</item>
@@ -106,7 +106,7 @@
 		<item name="android:textColorPrimary">@color/cpp_wizard_primary</item>
 	</style>
 
-	<style name="Cpp.Theme.Wizard" parent="Cpp.Theme">
+	<style name="Cpp.Theme.Wizard.Light" parent="Cpp.Theme.Material.Light">
 		<item name="android:windowBackground">@color/cpp_wizard_bg</item>
 		<item name="android:colorEdgeEffect">@color/cpp_wizard_overscroll</item>
 		<item name="colorAccent">@color/cpp_wizard_primary</item>