diff --git a/app/build.gradle b/app/build.gradle
index 9cddbf8..39f322a 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -8,7 +8,7 @@ android {
     compileSdkVersion 27
     defaultConfig {
         applicationId "com.divyanshu.androiddraw"
-        minSdkVersion 21
+        minSdkVersion 15
         targetSdkVersion 27
         versionCode 3
         versionName "1.0.2"
diff --git a/draw/build.gradle b/draw/build.gradle
index a78303e..16bf48d 100644
--- a/draw/build.gradle
+++ b/draw/build.gradle
@@ -6,7 +6,7 @@ android {
 
 
     defaultConfig {
-        minSdkVersion 19
+        minSdkVersion 15
         targetSdkVersion 27
         versionCode 1
         versionName "1.0"
diff --git a/draw/src/main/res/layout/activity_drawing.xml b/draw/src/main/res/layout/activity_drawing.xml
index 0814123..0669934 100644
--- a/draw/src/main/res/layout/activity_drawing.xml
+++ b/draw/src/main/res/layout/activity_drawing.xml
@@ -21,6 +21,7 @@
         android:padding="12dp"
         android:layout_margin="10dp"
         app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintLeft_toLeftOf="parent"
         app:layout_constraintTop_toTopOf="parent"
         android:background="@color/color_white"
         android:foreground="?selectableItemBackgroundBorderless" />
@@ -34,7 +35,9 @@
         android:tint="@color/color_white"
         app:layout_constraintTop_toTopOf="@id/image_close_drawing"
         android:layout_marginEnd="10dp"
+        android:layout_marginRight="10dp"
         app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintRight_toRightOf="parent"
         app:fabSize="mini"/>
 
     <android.support.constraint.ConstraintLayout
@@ -43,6 +46,8 @@
         android:layout_height="wrap_content"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintLeft_toLeftOf="parent"
+        app:layout_constraintRight_toRightOf="parent"
         app:layout_constraintBottom_toBottomOf="parent"
         android:background="@color/color_white"
         android:elevation="4dp"
@@ -59,6 +64,8 @@
             app:layout_constraintHorizontal_chainStyle="packed"
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintEnd_toStartOf="@id/image_draw_width"
+            app:layout_constraintLeft_toLeftOf="parent"
+            app:layout_constraintRight_toLeftOf="@id/image_draw_width"
             app:layout_constraintTop_toTopOf="parent" />
 
         <ImageView
@@ -71,6 +78,8 @@
             android:foreground="?selectableItemBackground"
             app:layout_constraintStart_toEndOf="@id/image_draw_eraser"
             app:layout_constraintEnd_toStartOf="@id/image_draw_color"
+            app:layout_constraintLeft_toRightOf="@id/image_draw_eraser"
+            app:layout_constraintRight_toLeftOf="@id/image_draw_color"
             app:layout_constraintTop_toTopOf="parent"/>
 
         <ImageView
@@ -83,6 +92,8 @@
             android:foreground="?selectableItemBackground"
             app:layout_constraintStart_toEndOf="@id/image_draw_width"
             app:layout_constraintEnd_toStartOf="@id/image_draw_opacity"
+            app:layout_constraintLeft_toRightOf="@id/image_draw_width"
+            app:layout_constraintRight_toLeftOf="@id/image_draw_opacity"
             app:layout_constraintTop_toTopOf="parent"/>
 
         <ImageView
@@ -95,6 +106,8 @@
             android:foreground="?selectableItemBackground"
             app:layout_constraintStart_toEndOf="@id/image_draw_color"
             app:layout_constraintEnd_toStartOf="@id/image_draw_undo"
+            app:layout_constraintLeft_toRightOf="@id/image_draw_color"
+            app:layout_constraintRight_toLeftOf="@id/image_draw_undo"
             app:layout_constraintTop_toTopOf="parent"/>
 
         <ImageView
@@ -107,6 +120,8 @@
             android:foreground="?selectableItemBackground"
             app:layout_constraintStart_toEndOf="@id/image_draw_opacity"
             app:layout_constraintEnd_toStartOf="@id/image_draw_redo"
+            app:layout_constraintLeft_toRightOf="@id/image_draw_opacity"
+            app:layout_constraintRight_toLeftOf="@id/image_draw_redo"
             app:layout_constraintTop_toTopOf="parent" />
 
         <ImageView
@@ -119,43 +134,61 @@
             android:foreground="?selectableItemBackground"
             app:layout_constraintStart_toEndOf="@id/image_draw_undo"
             app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintLeft_toRightOf="@id/image_draw_undo"
+            app:layout_constraintRight_toRightOf="parent"
             app:layout_constraintTop_toTopOf="parent" />
 
+        <!-- https://stackoverflow.com/questions/7404100/how-to-fix-seekbar-bar-thumb-centering-issues/7404421 -->
         <SeekBar
             android:id="@+id/seekBar_width"
             android:layout_width="0dp"
             android:layout_height="56dp"
+            android:minHeight="56dip"
+            android:maxHeight="56dip"
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintEnd_toStartOf="@+id/circle_view_width"
+            app:layout_constraintLeft_toLeftOf="parent"
+            app:layout_constraintRight_toLeftOf="@+id/circle_view_width"
             app:layout_constraintTop_toBottomOf="@id/image_draw_eraser"
             android:progress="8"
             android:paddingStart="16dp"
-            android:paddingEnd="16dp" />
+            android:paddingEnd="16dp"
+            android:paddingLeft="16dp"
+            android:paddingRight="16dp" />
 
         <com.divyanshu.draw.widget.CircleView
             android:id="@+id/circle_view_width"
             android:layout_width="56dp"
             android:layout_height="56dp"
             app:layout_constraintTop_toBottomOf="@id/image_draw_eraser"
-            app:layout_constraintEnd_toEndOf="parent" />
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintRight_toRightOf="parent" />
 
+        <!-- https://stackoverflow.com/questions/7404100/how-to-fix-seekbar-bar-thumb-centering-issues/7404421 -->
         <SeekBar
             android:id="@+id/seekBar_opacity"
             android:layout_width="0dp"
             android:layout_height="56dp"
+            android:minHeight="56dip"
+            android:maxHeight="56dip"
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintEnd_toStartOf="@+id/circle_view_opacity"
+            app:layout_constraintLeft_toLeftOf="parent"
+            app:layout_constraintRight_toLeftOf="@+id/circle_view_opacity"
             app:layout_constraintTop_toBottomOf="@id/image_draw_eraser"
             android:progress="100"
             android:paddingStart="16dp"
-            android:paddingEnd="16dp" />
+            android:paddingEnd="16dp"
+            android:paddingLeft="16dp"
+            android:paddingRight="16dp" />
 
         <com.divyanshu.draw.widget.CircleView
             android:id="@+id/circle_view_opacity"
             android:layout_width="56dp"
             android:layout_height="56dp"
             app:layout_constraintTop_toBottomOf="@id/image_draw_eraser"
-            app:layout_constraintEnd_toEndOf="parent" />
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintRight_toRightOf="parent" />
 
         <include
             android:id="@+id/draw_color_palette"
@@ -164,6 +197,8 @@
             android:layout_height="56dp"
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintLeft_toLeftOf="parent"
+            app:layout_constraintRight_toRightOf="parent"
             app:layout_constraintTop_toBottomOf="@id/image_draw_eraser" />
 
     </android.support.constraint.ConstraintLayout>
diff --git a/draw/src/main/res/layout/color_palette_view.xml b/draw/src/main/res/layout/color_palette_view.xml
index 39a965a..b1a0db7 100644
--- a/draw/src/main/res/layout/color_palette_view.xml
+++ b/draw/src/main/res/layout/color_palette_view.xml
@@ -14,6 +14,8 @@
         android:paddingBottom="16dp"
         android:paddingStart="12dp"
         android:paddingEnd="12dp"
+        android:paddingLeft="12dp"
+        android:paddingRight="12dp"
         android:scaleY="1.5"
         android:scaleX="1.5"/>
 
@@ -25,7 +27,9 @@
         android:paddingTop="16dp"
         android:paddingBottom="16dp"
         android:paddingStart="12dp"
-        android:paddingEnd="12dp" />
+        android:paddingEnd="12dp"
+        android:paddingLeft="12dp"
+        android:paddingRight="12dp" />
 
     <ImageView
         android:id="@+id/image_color_yellow"
@@ -35,7 +39,9 @@
         android:paddingTop="16dp"
         android:paddingBottom="16dp"
         android:paddingStart="12dp"
-        android:paddingEnd="12dp" />
+        android:paddingEnd="12dp"
+        android:paddingLeft="12dp"
+        android:paddingRight="12dp" />
 
     <ImageView
         android:id="@+id/image_color_green"
@@ -45,7 +51,9 @@
         android:paddingTop="16dp"
         android:paddingBottom="16dp"
         android:paddingStart="12dp"
-        android:paddingEnd="12dp" />
+        android:paddingEnd="12dp"
+        android:paddingLeft="12dp"
+        android:paddingRight="12dp" />
 
     <ImageView
         android:id="@+id/image_color_blue"
@@ -55,7 +63,9 @@
         android:paddingTop="16dp"
         android:paddingBottom="16dp"
         android:paddingStart="12dp"
-        android:paddingEnd="12dp" />
+        android:paddingEnd="12dp"
+        android:paddingLeft="12dp"
+        android:paddingRight="12dp" />
 
     <ImageView
         android:id="@+id/image_color_pink"
@@ -65,7 +75,9 @@
         android:paddingTop="16dp"
         android:paddingBottom="16dp"
         android:paddingStart="12dp"
-        android:paddingEnd="12dp" />
+        android:paddingEnd="12dp"
+        android:paddingLeft="12dp"
+        android:paddingRight="12dp" />
 
     <ImageView
         android:id="@+id/image_color_brown"
@@ -75,5 +87,7 @@
         android:paddingTop="16dp"
         android:paddingBottom="16dp"
         android:paddingStart="12dp"
-        android:paddingEnd="12dp" />
+        android:paddingEnd="12dp"
+        android:paddingLeft="12dp"
+        android:paddingRight="12dp" />
 </LinearLayout>
\ No newline at end of file