diff --git a/res/layout/calc_history_button.xml b/res/layout/calc_history_button.xml
index 5b604df1..d162759a 100644
--- a/res/layout/calc_history_button.xml
+++ b/res/layout/calc_history_button.xml
@@ -11,7 +11,7 @@
 													   a:text="@string/c_history_button"
 													   c:textUp="@string/c_undo"
 													   c:textDown="@string/c_redo"
-													   c:directionTextScale="0.3"
+													   c:directionTextScale="0.27"
 													   style="?controlButtonStyle"
 													   a:textStyle="bold"
 													   a:onClick="historyButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/values-es/text_functions.xml b/res/values-es/text_functions.xml
index b6256dc0..bfa39970 100644
--- a/res/values-es/text_functions.xml
+++ b/res/values-es/text_functions.xml
@@ -18,6 +18,7 @@
 	<string name="c_fun_description_acot">Arccotangente - El inverso de la función cotangente.</string>
 	<string name="c_fun_description_ln">Logaritmo neperiano - logaritmo de base e.</string>
 	<string name="c_fun_description_lg">Decadic logaritmo - logaritmo de base 10.</string>
+	<string name="c_fun_description_log">Logaritmo - logaritmo de la base especificada.</string>
 	<string name="c_fun_description_exp">Función exponencial.</string>
 	<string name="c_fun_description_sqrt">Función Raíz cuadrado.</string>
 	<string name="c_fun_description_cubic">Función Raíz cuadrada.</string>
diff --git a/res/values-es/text_strings.xml b/res/values-es/text_strings.xml
index 462ac1fc..c33c5187 100644
--- a/res/values-es/text_strings.xml
+++ b/res/values-es/text_strings.xml
@@ -120,8 +120,8 @@
 
 	<string name="c_empty_var_error">No se puede crear una constante vacía!</string>
 	<string name="c_not_valid_result">El resultado actual no es válido!</string>
-	<!--
-		<string name="c_plot_graph">Graph</string>
+
+	<string name="c_plot_graph">Gráfico</string>
 	<string name="c_min_x_value">From</string>
 	<string name="c_max_x_value">To</string>
 
@@ -129,25 +129,28 @@
 	<string name="c_swipe_distance_summary">Sets swipe distance for buttons that support additional swipe actions</string>
 
 	<string name="c_comment">Comment</string>
-	<string name="c_history_item_saved">Saved</string>
-	<string name="c_history_item_not_saved">Not saved</string>
-	<string name="c_expression_copied">Expression copied to the clipboard!</string>
-	<string name="c_history_item_status">Status: </string>
-	<string name="c_history_item_comment">Comment: </string>
-	<string name="c_use">Use</string>
-	<string name="c_copy_expression">Copy expression</string>
-	<string name="c_copy_result">Copy result</string>
-	<string name="c_history_expression">Value</string>
-	<string name="c_history_item_already_saved">Saved (see \'Saved history\' tab)</string>
-	<string name="c_history_comment">Comment</string>
-	<string name="c_save_history">Save history</string>
-	<string name="c_edit_history">Modify history</string>
-	<string name="c_edit">Modify</string>
-	<string name="c_saved_history">Saved history</string>
+	<string name="c_history_item_saved">Guardado</string>
+	<string name="c_history_item_not_saved">No se guarda</string>
+	<string name="c_expression_copied">Expresión copiada en el portapapeles!</string>
+	<string name="c_history_item_status">Estado: </string>
+	<string name="c_history_item_comment">Comentario: </string>
+	<string name="c_use">Utilizar</string>
+	<string name="c_copy_expression">Copia de la expresión</string>
+	<string name="c_copy_result">Copia resultado</string>
+	<string name="c_history_expression">Valor</string>
+	<string name="c_history_item_already_saved">Salvo (ver \'La historia guardada\' ficha)</string>
+	<string name="c_history_comment">Comentario</string>
+	<string name="c_save_history">Guardar el historial de</string>
+	<string name="c_edit_history">Modificar la historia</string>
+	<string name="c_edit">modificar</string>
+	<string name="c_saved_history">La historia guardada</string>
+
+	<string name="c_history_already_saved">La historia se salvó ya!</string>
+	<string name="c_history_must_be_saved">La historia debe ser salvado antes de editar!</string>
+	<string name="c_history_was_removed">La historia se ha eliminado correctamente!</string>
+	<string name="c_history_saved">La historia se ha guardado correctamente!</string>
+
+	<string name="c_copy_description">Сopia de la descripción</string>
+	<string name="c_copy_value">Сopia el valor</string>
 
-	<string name="c_history_already_saved">History was already saved!</string>
-	<string name="c_history_must_be_saved">History must be saved before editing!</string>
-	<string name="c_history_was_removed">History was successfully removed!</string>
-	<string name="c_history_saved">History was successfully saved!</string>
-	-->
 </resources>
\ No newline at end of file
diff --git a/res/values-it/text_functions.xml b/res/values-it/text_functions.xml
index b64c093c..92f59bcf 100644
--- a/res/values-it/text_functions.xml
+++ b/res/values-it/text_functions.xml
@@ -18,6 +18,7 @@
 	<string name="c_fun_description_acot">Arccotangente - inversa della funzione cotangente.</string>
 	<string name="c_fun_description_ln">Logaritmo naturale - logaritmo in base e.</string>
 	<string name="c_fun_description_lg">Logaritmo decimale - logaritmo in base 10.</string>
+	<string name="c_fun_description_log">Logaritmo - logaritmo nella base specificata.</string>
 	<string name="c_fun_description_exp">Funzione esponenziale.</string>
 	<string name="c_fun_description_sqrt">Funzione radice quadrata.</string>
 	<string name="c_fun_description_cubic">Funzione radice cubica.</string>
diff --git a/res/values-it/text_strings.xml b/res/values-it/text_strings.xml
index 1054b4a9..3dd4d734 100644
--- a/res/values-it/text_strings.xml
+++ b/res/values-it/text_strings.xml
@@ -150,4 +150,7 @@
 	<string name="c_history_was_removed">La storia è stata rimossa con successo!</string>
 	<string name="c_history_saved">La storia è stata salvata correttamente!</string>
 
+	<string name="c_copy_description">Сopia descrizione</string>
+	<string name="c_copy_value">Сopia il valore</string>
+
 </resources>
\ No newline at end of file
diff --git a/res/values-ru/text_about.xml b/res/values-ru/text_about.xml
index ba9d5236..4ba996eb 100644
--- a/res/values-ru/text_about.xml
+++ b/res/values-ru/text_about.xml
@@ -16,7 +16,7 @@
 		Если вам понравилось приложение -\nпоставьте 5 звёздочек в\n<a href="https://market.android.com/details?id=org.solovyev.android.calculator">андроид.маркете</a>\n\n
 		Спасибо тем, кто переводил Калькулятор++:\n
 		на итальянский - Gabriele Ravanetti\n
-		на испанский - Jordi Luna\т\n
+		на испанский - Jordi Luna\n\n
 		Это приложение использует следующие открытые библиотеки:\n
 		<a href="http://simple.sourceforge.net">Simple (XML serialization)</a>\n
 		<a href="http://meditorworld.appspot.com/meditor.txt">JSCL</a>\n
diff --git a/res/values-ru/text_functions.xml b/res/values-ru/text_functions.xml
index 57c66937..abc42cc1 100644
--- a/res/values-ru/text_functions.xml
+++ b/res/values-ru/text_functions.xml
@@ -18,6 +18,7 @@
 	<string name="c_fun_description_acot">Арккотангенс - обратная функция к котангенсу.</string>
 	<string name="c_fun_description_ln">Натуральный логарифм - логарифм по основанию e.</string>
 	<string name="c_fun_description_lg">Десятичный логарифм - логарифм по основанию 10.</string>
+	<string name="c_fun_description_log">Логирифм по заданному основанию.</string>
 	<string name="c_fun_description_exp">Экспонента.</string>
 	<string name="c_fun_description_sqrt">Функция квадратного корня.</string>
 	<string name="c_fun_description_cubic">Функция кубического корня.</string>
diff --git a/res/values-ru/text_strings.xml b/res/values-ru/text_strings.xml
index a263d8e9..f5caab72 100644
--- a/res/values-ru/text_strings.xml
+++ b/res/values-ru/text_strings.xml
@@ -150,4 +150,7 @@
 	<string name="c_history_was_removed">История успешно удалена!</string>
 	<string name="c_history_saved">История успешно сохранена!</string>
 
+	<string name="c_copy_description">Копироват описание</string>
+	<string name="c_copy_value">Копировать значение</string>
+
 </resources>
\ No newline at end of file
diff --git a/res/values/attrs.xml b/res/values/attrs.xml
index 5724143c..d685f2f7 100644
--- a/res/values/attrs.xml
+++ b/res/values/attrs.xml
@@ -1,11 +1,15 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-	<declare-styleable name="DragButton">
+	<declare-styleable name="DirectionDragButton">
 		<attr name="textUp" format="string"/>
 		<attr name="textDown" format="string"/>
 		<attr name="textRight" format="string"/>
 		<attr name="textLeft" format="string"/>
 		<attr name="directionTextScale" format="string"/>
+		<attr name="directionTextAlpha" format="integer"/>
+	</declare-styleable>
+
+	<declare-styleable name="DragButton">
 		<attr name="hTextPosition" format="float"/>
 	</declare-styleable>
 
diff --git a/res/values/text_functions.xml b/res/values/text_functions.xml
index cb8049bf..e866b0d3 100644
--- a/res/values/text_functions.xml
+++ b/res/values/text_functions.xml
@@ -18,6 +18,7 @@
 	<string name="c_fun_description_acot">Arccotangent - the inverse of cotangent function.</string>
 	<string name="c_fun_description_ln">Natural logarithm - logarithm the base e.</string>
 	<string name="c_fun_description_lg">Decadic logarithm - logarithm the base 10.</string>
+	<string name="c_fun_description_log">Logarithm - logarithm the specified base.</string>
 	<string name="c_fun_description_exp">Exponential function.</string>
 	<string name="c_fun_description_sqrt">Square root function.</string>
 	<string name="c_fun_description_cubic">Cubic root function.</string>
diff --git a/src/main/java/org/solovyev/android/calculator/model/AndroidFunctionsMathRegistry.java b/src/main/java/org/solovyev/android/calculator/model/AndroidFunctionsMathRegistry.java
index e7aa774f..c1f2fcb4 100644
--- a/src/main/java/org/solovyev/android/calculator/model/AndroidFunctionsMathRegistry.java
+++ b/src/main/java/org/solovyev/android/calculator/model/AndroidFunctionsMathRegistry.java
@@ -58,7 +58,7 @@ public class AndroidFunctionsMathRegistry extends AbstractAndroidMathRegistry<Fu
 			}
 		},
         
-        common(R.string.c_fun_category_common, 100) {
+        common(R.string.c_fun_category_common, 50) {
             @Override
             boolean isInCategory(@NotNull Function function) {
                 for (Category category : values()) {
@@ -120,7 +120,7 @@ public class AndroidFunctionsMathRegistry extends AbstractAndroidMathRegistry<Fu
 	public void load(@Nullable Context context, @Nullable SharedPreferences preferences) {
 		super.load(context, preferences);
 
-		add(new CustomFunction.Builder(true, "log", new String[]{"a", "b"}, "ln(b)/ln(a)"));
+		add(new CustomFunction.Builder(true, "log", new String[]{"base", "x"}, "ln(x)/ln(base)"));
 	}
 
 	@NotNull
diff --git a/src/main/java/org/solovyev/android/view/widgets/AngleUnitsButton.java b/src/main/java/org/solovyev/android/view/widgets/AngleUnitsButton.java
index 1ece9285..4a3bd30e 100644
--- a/src/main/java/org/solovyev/android/view/widgets/AngleUnitsButton.java
+++ b/src/main/java/org/solovyev/android/view/widgets/AngleUnitsButton.java
@@ -37,7 +37,7 @@ public class AngleUnitsButton extends DirectionDragButton {
 			directionTextPaint.setColor(resources.getColor(R.color.selected_angle_unit_text_color));
 		} else {
 			directionTextPaint.setColor(resources.getColor(R.color.default_text_color));
-			directionTextPaint.setAlpha(getDefaultDirectionTextAlpha());
+			directionTextPaint.setAlpha(getDirectionTextAlpha());
 		}
 	}
 }
diff --git a/src/main/java/org/solovyev/android/view/widgets/ColorButton.java b/src/main/java/org/solovyev/android/view/widgets/ColorButton.java
index b3be0770..2c71b923 100644
--- a/src/main/java/org/solovyev/android/view/widgets/ColorButton.java
+++ b/src/main/java/org/solovyev/android/view/widgets/ColorButton.java
@@ -23,6 +23,7 @@ package org.solovyev.android.view.widgets;
 
 import android.content.Context;
 import android.content.res.Resources;
+import android.content.res.TypedArray;
 import android.graphics.Canvas;
 import android.graphics.Paint;
 import android.graphics.Paint.Style;
@@ -64,7 +65,6 @@ public class ColorButton extends Button {
 
 	private static final float H_TEXT_POSITION_DEFAULT_VALUE = 0.5f;
 
-	// todo serso: check - currently not worked
 	private float hTextPosition = H_TEXT_POSITION_DEFAULT_VALUE;
 
 	public ColorButton(Context context, AttributeSet attrs) {
@@ -74,6 +74,22 @@ public class ColorButton extends Button {
 	public ColorButton(Context context, AttributeSet attrs, boolean init) {
 		super(context, attrs);
 
+		TypedArray a = context.obtainStyledAttributes(attrs, org.solovyev.android.calculator.R.styleable.DragButton);
+		final int N = a.getIndexCount();
+		for (int i = 0; i < N; i++) {
+			int attr = a.getIndex(i);
+
+			final String attrValue = a.getString(attr);
+
+			if (!StringUtils.isEmpty(attrValue)) {
+				switch (attr) {
+					case R.styleable.DragButton_hTextPosition:
+						this.hTextPosition = Float.valueOf(attrValue);
+						break;
+				}
+			}
+		}
+		
 		if (init) {
 			init(context);
 		}
@@ -219,14 +235,6 @@ public class ColorButton extends Button {
 	 	this.onClickListener.onClick(this);
 	}
 
-	public float getHTextPosition() {
-		return hTextPosition;
-	}
-
-	public void setHTextPosition(float hTextPosition) {
-		this.hTextPosition = hTextPosition;
-	}
-
 	@Override
 	public boolean onTouchEvent(MotionEvent event) {
 		boolean result = super.onTouchEvent(event);
diff --git a/src/main/java/org/solovyev/android/view/widgets/DirectionDragButton.java b/src/main/java/org/solovyev/android/view/widgets/DirectionDragButton.java
index 7e849d9b..e4279f08 100644
--- a/src/main/java/org/solovyev/android/view/widgets/DirectionDragButton.java
+++ b/src/main/java/org/solovyev/android/view/widgets/DirectionDragButton.java
@@ -35,6 +35,9 @@ public class DirectionDragButton extends DragButton {
 	@NotNull
 	private final static Float DEFAULT_DIRECTION_TEXT_SCALE_FLOAT = 0.33f;
 
+	@NotNull
+	private final static Integer DEFAULT_DIRECTION_TEXT_ALPHA = 140;
+
 	@NotNull
 	private final static String DEFAULT_DIRECTION_TEXT_SCALE = "0.33;0.33;0.33;0.33";
 
@@ -106,7 +109,7 @@ public class DirectionDragButton extends DragButton {
 		up(DragDirection.up, 0) {
 			@Override
 			public int getAttributeId() {
-				return R.styleable.DragButton_textUp;
+				return R.styleable.DirectionDragButton_textUp;
 			}
 
 			@NotNull
@@ -118,7 +121,7 @@ public class DirectionDragButton extends DragButton {
 		down(DragDirection.down, 2) {
 			@Override
 			public int getAttributeId() {
-				return R.styleable.DragButton_textDown;
+				return R.styleable.DirectionDragButton_textDown;
 			}
 
 			@NotNull
@@ -130,7 +133,7 @@ public class DirectionDragButton extends DragButton {
 		left(DragDirection.left, 3) {
 			@Override
 			public int getAttributeId() {
-				return R.styleable.DragButton_textLeft;
+				return R.styleable.DirectionDragButton_textLeft;
 			}
 
 			@NotNull
@@ -143,7 +146,7 @@ public class DirectionDragButton extends DragButton {
 		right(DragDirection.right, 1) {
 			@Override
 			public int getAttributeId() {
-				return R.styleable.DragButton_textRight;
+				return R.styleable.DirectionDragButton_textRight;
 			}
 
 			@NotNull
@@ -230,6 +233,9 @@ public class DirectionDragButton extends DragButton {
 	@NotNull
 	private String directionTextScale = DEFAULT_DIRECTION_TEXT_SCALE;
 
+	@NotNull
+	private Integer directionTextAlpha = DEFAULT_DIRECTION_TEXT_ALPHA;
+
 	private boolean initialized = false;
 
 	public DirectionDragButton(Context context, @NotNull AttributeSet attrs) {
@@ -239,7 +245,7 @@ public class DirectionDragButton extends DragButton {
 
 	private void init(@NotNull Context context, @NotNull AttributeSet attrs) {
 
-		TypedArray a = context.obtainStyledAttributes(attrs, org.solovyev.android.calculator.R.styleable.DragButton);
+		TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.DirectionDragButton);
 
 		final int N = a.getIndexCount();
 		for (int i = 0; i < N; i++) {
@@ -249,9 +255,12 @@ public class DirectionDragButton extends DragButton {
 
 			if (!StringUtils.isEmpty(attrValue)) {
 				switch (attr) {
-					case R.styleable.DragButton_directionTextScale:
+					case R.styleable.DirectionDragButton_directionTextScale:
 						this.directionTextScale = attrValue;
 						break;
+					case R.styleable.DirectionDragButton_directionTextAlpha:
+						this.directionTextAlpha = Integer.valueOf(attrValue);
+						break;
 					default:
 						// try drag direction text
 						for (GuiDragDirection guiDragDirection : GuiDragDirection.values()) {
@@ -318,14 +327,14 @@ public class DirectionDragButton extends DragButton {
 		final TextPaint directionTextPaint = new TextPaint(basePaint);
 
 		directionTextPaint.setColor(resources.getColor(R.color.button_text_color));
-		directionTextPaint.setAlpha(getDefaultDirectionTextAlpha());
+		directionTextPaint.setAlpha(getDirectionTextAlpha());
 		directionTextPaint.setTextSize(basePaint.getTextSize() * directionTextData.getTextScale());
 
 		directionTextData.setPaint(directionTextPaint);
 	}
 
-	protected static int getDefaultDirectionTextAlpha() {
-		return 120;
+	protected int getDirectionTextAlpha() {
+		return directionTextAlpha;
 	}
 
 	@Nullable
diff --git a/src/main/java/org/solovyev/android/view/widgets/NumeralBasesButton.java b/src/main/java/org/solovyev/android/view/widgets/NumeralBasesButton.java
index 5d8f81c2..1160bdd6 100644
--- a/src/main/java/org/solovyev/android/view/widgets/NumeralBasesButton.java
+++ b/src/main/java/org/solovyev/android/view/widgets/NumeralBasesButton.java
@@ -37,7 +37,7 @@ public class NumeralBasesButton extends DirectionDragButton {
 			directionTextPaint.setColor(resources.getColor(R.color.selected_angle_unit_text_color));
 		} else {
 			directionTextPaint.setColor(resources.getColor(R.color.default_text_color));
-			directionTextPaint.setAlpha(getDefaultDirectionTextAlpha());
+			directionTextPaint.setAlpha(getDirectionTextAlpha());
 		}
 	}
 }