diff --git a/android-app/src/main/java/org/solovyev/android/calculator/Preferences.java b/android-app/src/main/java/org/solovyev/android/calculator/Preferences.java
index 438c846d..e5d50dcc 100644
--- a/android-app/src/main/java/org/solovyev/android/calculator/Preferences.java
+++ b/android-app/src/main/java/org/solovyev/android/calculator/Preferences.java
@@ -101,29 +101,22 @@ public final class Preferences {
 
 		public static enum Theme {
 
-			default_theme(ThemeType.other, R.style.cpp_gray_theme),
-			violet_theme(ThemeType.other, R.style.cpp_violet_theme),
-			light_blue_theme(ThemeType.other, R.style.cpp_light_blue_theme),
-			metro_blue_theme(ThemeType.metro, R.style.cpp_metro_blue_theme),
-			metro_purple_theme(ThemeType.metro, R.style.cpp_metro_purple_theme),
-			metro_green_theme(ThemeType.metro, R.style.cpp_metro_green_theme);
-
-			@Nonnull
-			private final ThemeType themeType;
+			default_theme(R.style.cpp_gray_theme),
+			violet_theme(R.style.cpp_violet_theme),
+			light_blue_theme(R.style.cpp_light_blue_theme),
+			metro_blue_theme(R.style.cpp_metro_blue_theme),
+			metro_purple_theme(R.style.cpp_metro_purple_theme),
+			metro_green_theme(R.style.cpp_metro_green_theme),
+			material_theme(R.style.cpp_material_theme),
+			;
 
 			@Nonnull
 			private final Integer themeId;
 
-			Theme(@Nonnull ThemeType themeType, @Nonnull Integer themeId) {
-				this.themeType = themeType;
+			Theme(@Nonnull Integer themeId) {
 				this.themeId = themeId;
 			}
 
-			@Nonnull
-			public ThemeType getThemeType() {
-				return themeType;
-			}
-
 			@Nonnull
 			public Integer getThemeId() {
 				return getThemeId(null);
@@ -137,12 +130,6 @@ public final class Preferences {
 				return themeId;
 			}
 		}
-
-		public static enum ThemeType {
-			metro,
-			other
-		}
-
 		public static enum Layout {
 			main_calculator(R.layout.main_calculator, R.string.p_layout_calculator, true),
 			main_calculator_mobile(R.layout.main_calculator_mobile, R.string.p_layout_calculator_mobile, false),
diff --git a/android-app/src/main/res/drawable-v21/material_blue_button.xml b/android-app/src/main/res/drawable-v21/material_blue_button.xml
new file mode 100644
index 00000000..5f9f634d
--- /dev/null
+++ b/android-app/src/main/res/drawable-v21/material_blue_button.xml
@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright 2013 serso aka se.solovyev
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~    http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  ~
+  ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  ~ Contact details
+  ~
+  ~ Email: se.solovyev@gmail.com
+  ~ Site:  http://se.solovyev.org
+  -->
+
+<ripple xmlns:a="http://schemas.android.com/apk/res/android"
+	a:color="?attr/colorControlHighlight">
+	<item>
+		<shape>
+			<solid a:color="@color/cpp_material_blue" />
+		</shape>
+	</item>
+</ripple>
diff --git a/android-app/src/main/res/drawable-v21/material_button_dark.xml b/android-app/src/main/res/drawable-v21/material_button_dark.xml
new file mode 100644
index 00000000..97c0ea90
--- /dev/null
+++ b/android-app/src/main/res/drawable-v21/material_button_dark.xml
@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright 2013 serso aka se.solovyev
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~    http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  ~
+  ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  ~ Contact details
+  ~
+  ~ Email: se.solovyev@gmail.com
+  ~ Site:  http://se.solovyev.org
+  -->
+
+<ripple xmlns:a="http://schemas.android.com/apk/res/android"
+	a:color="?attr/colorControlHighlight">
+	<item>
+		<shape>
+			<solid a:color="@color/cpp_metro_button" />
+		</shape>
+	</item>
+</ripple>
\ No newline at end of file
diff --git a/android-app/src/main/res/drawable-v21/material_button_light.xml b/android-app/src/main/res/drawable-v21/material_button_light.xml
new file mode 100644
index 00000000..d26ac324
--- /dev/null
+++ b/android-app/src/main/res/drawable-v21/material_button_light.xml
@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright 2013 serso aka se.solovyev
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~    http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  ~
+  ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  ~ Contact details
+  ~
+  ~ Email: se.solovyev@gmail.com
+  ~ Site:  http://se.solovyev.org
+  -->
+
+<ripple xmlns:a="http://schemas.android.com/apk/res/android"
+	a:color="?attr/colorControlHighlight">
+	<item>
+		<shape>
+			<solid a:color="@color/cpp_metro_button_light" />
+		</shape>
+	</item>
+</ripple>
\ No newline at end of file
diff --git a/android-app/src/main/res/values-v21/theme_material.xml b/android-app/src/main/res/values-v21/theme_material.xml
new file mode 100644
index 00000000..92055bbe
--- /dev/null
+++ b/android-app/src/main/res/values-v21/theme_material.xml
@@ -0,0 +1,55 @@
+<!--
+  ~ Copyright 2013 serso aka se.solovyev
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~    http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  ~
+  ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  ~ Contact details
+  ~
+  ~ Email: se.solovyev@gmail.com
+  ~ Site:  http://se.solovyev.org
+  -->
+
+<resources>
+
+	<style name="material_digit_button_style" parent="cpp_keyboard_button_style">
+		<item name="android:background">@drawable/material_button_dark</item>
+	</style>
+
+	<style name="material_control_button_style" parent="metro_digit_button_style">
+		<item name="android:background">@drawable/material_button_dark</item>
+	</style>
+
+	<style name="material_operation_button_style" parent="material_digit_button_style">
+		<item name="android:background">@drawable/material_blue_button</item>
+	</style>
+
+	<style name="material_control_image_button_style" parent="material_control_button_style">
+		<item name="android:padding">6dp</item>
+	</style>
+
+	<style name="cpp_material_theme" parent="cpp_metro_blue_theme">
+		<item name="cpp_digit_button_style">@style/material_digit_button_style</item>
+		<item name="cpp_control_button_style">@style/material_control_button_style</item>
+		<item name="cpp_control_image_button_style">@style/material_control_image_button_style</item>
+		<item name="cpp_operation_button_style">@style/material_operation_button_style</item>
+	</style>
+
+	<style name="cpp_metro_blue_dialog_theme" parent="cpp_gray_dialog_theme">
+		<item name="cpp_digit_button_style">@style/material_digit_button_style</item>
+		<item name="cpp_control_button_style">@style/material_control_button_style</item>
+		<item name="cpp_control_image_button_style">@style/material_control_image_button_style</item>
+		<item name="cpp_operation_button_style">@style/material_operation_button_style</item>
+	</style>
+
+</resources>
\ No newline at end of file
diff --git a/android-app/src/main/res/values/colors.xml b/android-app/src/main/res/values/colors.xml
index 683cf68b..85ee23ce 100644
--- a/android-app/src/main/res/values/colors.xml
+++ b/android-app/src/main/res/values/colors.xml
@@ -41,6 +41,7 @@
 	<color name="cpp_metro_button">#212121</color>
 	<color name="cpp_metro_button_light">#393939</color>
 	<color name="cpp_metro_blue">#10648c</color>
+	<color name="cpp_material_blue">#ff0d4663</color>
 	<color name="cpp_metro_blue_dark">#ff092c39</color>
 	<color name="cpp_metro_green">#088e3a</color>
 	<color name="cpp_metro_purple">#651456</color>