diff --git a/app/src/main/kotlin/com/simplemobiletools/thankyou/activities/MainActivity.kt b/app/src/main/kotlin/com/simplemobiletools/thankyou/activities/MainActivity.kt
index 83b583e..518155e 100644
--- a/app/src/main/kotlin/com/simplemobiletools/thankyou/activities/MainActivity.kt
+++ b/app/src/main/kotlin/com/simplemobiletools/thankyou/activities/MainActivity.kt
@@ -1,13 +1,17 @@
 package com.simplemobiletools.thankyou.activities
 
 import android.os.Bundle
-import android.support.v7.app.AppCompatActivity
 import com.simplemobiletools.thankyou.R
 
-class MainActivity : AppCompatActivity() {
+class MainActivity : SimpleActivity() {
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
     }
+
+    override fun onDestroy() {
+        super.onDestroy()
+        mConfig.isFirstRun = false
+    }
 }
diff --git a/app/src/main/kotlin/com/simplemobiletools/thankyou/activities/SimpleActivity.kt b/app/src/main/kotlin/com/simplemobiletools/thankyou/activities/SimpleActivity.kt
new file mode 100644
index 0000000..7084233
--- /dev/null
+++ b/app/src/main/kotlin/com/simplemobiletools/thankyou/activities/SimpleActivity.kt
@@ -0,0 +1,27 @@
+package com.simplemobiletools.thankyou.activities
+
+import android.os.Bundle
+import android.support.v7.app.AppCompatActivity
+import android.view.MenuItem
+import com.simplemobiletools.thankyou.R
+import com.simplemobiletools.thankyou.helpers.Config
+
+open class SimpleActivity : AppCompatActivity() {
+    lateinit var mConfig: Config
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        mConfig = Config.newInstance(applicationContext)
+        setTheme(if (mConfig.isDarkTheme) R.style.AppTheme_Dark else R.style.AppTheme)
+        super.onCreate(savedInstanceState)
+    }
+
+    override fun onOptionsItemSelected(item: MenuItem): Boolean {
+        return when (item.itemId) {
+            android.R.id.home -> {
+                finish()
+                true
+            }
+            else -> super.onOptionsItemSelected(item)
+        }
+    }
+}
diff --git a/app/src/main/kotlin/com/simplemobiletools/thankyou/helpers/Config.kt b/app/src/main/kotlin/com/simplemobiletools/thankyou/helpers/Config.kt
new file mode 100644
index 0000000..59e0a79
--- /dev/null
+++ b/app/src/main/kotlin/com/simplemobiletools/thankyou/helpers/Config.kt
@@ -0,0 +1,24 @@
+package com.simplemobiletools.thankyou.helpers
+
+import android.content.Context
+import android.content.SharedPreferences
+
+class Config(context: Context) {
+    private val mPrefs: SharedPreferences
+
+    companion object {
+        fun newInstance(context: Context) = Config(context)
+    }
+
+    init {
+        mPrefs = context.getSharedPreferences(PREFS_KEY, Context.MODE_PRIVATE)
+    }
+
+    var isFirstRun: Boolean
+        get() = mPrefs.getBoolean(IS_FIRST_RUN, true)
+        set(firstRun) = mPrefs.edit().putBoolean(IS_FIRST_RUN, firstRun).apply()
+
+    var isDarkTheme: Boolean
+        get() = mPrefs.getBoolean(IS_DARK_THEME, false)
+        set(isDarkTheme) = mPrefs.edit().putBoolean(IS_DARK_THEME, isDarkTheme).apply()
+}
diff --git a/app/src/main/kotlin/com/simplemobiletools/thankyou/helpers/Constants.kt b/app/src/main/kotlin/com/simplemobiletools/thankyou/helpers/Constants.kt
new file mode 100644
index 0000000..1b14b37
--- /dev/null
+++ b/app/src/main/kotlin/com/simplemobiletools/thankyou/helpers/Constants.kt
@@ -0,0 +1,6 @@
+package com.simplemobiletools.thankyou.helpers
+
+// Shared Preferences
+val PREFS_KEY = "Thank You"
+val IS_FIRST_RUN = "is_first_run"
+val IS_DARK_THEME = "is_dark_theme"
diff --git a/app/src/main/res/values/colors.xml b/app/src/main/res/values/colors.xml
index 3ab3e9c..ca8ad63 100644
--- a/app/src/main/res/values/colors.xml
+++ b/app/src/main/res/values/colors.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-    <color name="colorPrimary">#3F51B5</color>
-    <color name="colorPrimaryDark">#303F9F</color>
-    <color name="colorAccent">#FF4081</color>
+    <color name="colorPrimary">#fff68630</color>
+    <color name="colorPrimaryDark">#ffe27725</color>
+    <color name="colorAccent">@color/colorPrimary</color>
 </resources>
diff --git a/app/src/main/res/values/dimens.xml b/app/src/main/res/values/dimens.xml
index e641ba4..26c3358 100644
--- a/app/src/main/res/values/dimens.xml
+++ b/app/src/main/res/values/dimens.xml
@@ -1,3 +1,5 @@
 <resources>
     <dimen name="activity_margin">16dp</dimen>
+
+    <dimen name="normal_text_size">14sp</dimen>
 </resources>
diff --git a/app/src/main/res/values/styles.xml b/app/src/main/res/values/styles.xml
index 5885930..89bc6b7 100644
--- a/app/src/main/res/values/styles.xml
+++ b/app/src/main/res/values/styles.xml
@@ -1,11 +1,29 @@
 <resources>
 
-    <!-- Base application theme. -->
     <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
-        <!-- Customize your theme here. -->
         <item name="colorPrimary">@color/colorPrimary</item>
         <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
         <item name="colorAccent">@color/colorAccent</item>
+        <item name="actionBarStyle">@style/AppTheme.ActionBarStyle</item>
+        <item name="android:textSize">@dimen/normal_text_size</item>
+    </style>
+
+    <style name="AppTheme.Dark" parent="Theme.AppCompat">
+        <item name="colorPrimary">@color/colorPrimary</item>
+        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
+        <item name="colorAccent">@color/colorAccent</item>
+        <item name="actionBarStyle">@style/AppTheme.ActionBarStyle</item>
+        <item name="android:textSize">@dimen/normal_text_size</item>
+        <item name="android:windowBackground">@android:color/black</item>
+    </style>
+
+    <style name="AppTheme.ActionBarStyle" parent="@style/Base.Widget.AppCompat.ActionBar">
+        <item name="background">@color/colorPrimary</item>
+        <item name="titleTextStyle">@style/AppTheme.ActionBar.TitleTextStyle</item>
+    </style>
+
+    <style name="AppTheme.ActionBar.TitleTextStyle" parent="@android:style/TextAppearance.Holo.Widget.ActionBar.Title">
+        <item name="android:textSize">20sp</item>
     </style>
 
 </resources>