diff --git a/app/build.gradle b/app/build.gradle
index 1c5fabd..3da3cf6 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -3,36 +3,26 @@ apply plugin: 'kotlin-android-extensions'
 apply plugin: 'kotlin-android'
 
 android {
-    compileSdkVersion 28
-    buildToolsVersion "28.0.3"
+    compileSdkVersion 29
+    buildToolsVersion "29.0.1"
 
     defaultConfig {
         applicationId "fr.corenting.convertisseureurofranc"
         minSdkVersion 14
-        targetSdkVersion 28
-        versionCode 9
-        versionName "2.0"
+        targetSdkVersion 29
+        versionCode 10
+        versionName "2.1"
     }
 
-    signingConfigs {
-        release {
-            try {
-                storeFile file(KEYSTORE_FILE)
-                storePassword KEYSTORE_PASSWORD
-                keyAlias KEY_ALIAS
-                keyPassword KEY_PASSWORD
-            }
-            catch (ex) {
-                throw ex
-            }
-        }
+    compileOptions {
+        sourceCompatibility 1.8
+        targetCompatibility 1.8
     }
 
     buildTypes {
         release {
             minifyEnabled true
             shrinkResources true
-            signingConfig signingConfigs.release
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
@@ -40,8 +30,9 @@ android {
 
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
-    implementation 'androidx.appcompat:appcompat:1.0.2'
-    implementation 'com.google.android.material:material:1.1.0-alpha03'
+    implementation 'androidx.core:core:1.0.2'
+    implementation 'androidx.preference:preference:1.0.0'
+    implementation 'com.google.android.material:material:1.0.0'
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
 }
 
diff --git a/app/src/main/java/fr/corenting/convertisseureurofranc/ConverterActivity.kt b/app/src/main/java/fr/corenting/convertisseureurofranc/ConverterActivity.kt
index 352548d..8ce9d46 100644
--- a/app/src/main/java/fr/corenting/convertisseureurofranc/ConverterActivity.kt
+++ b/app/src/main/java/fr/corenting/convertisseureurofranc/ConverterActivity.kt
@@ -2,20 +2,18 @@ package fr.corenting.convertisseureurofranc
 
 import android.content.SharedPreferences
 import android.os.Bundle
-import android.preference.PreferenceManager
 import android.view.KeyEvent
 import android.view.Menu
 import android.view.MenuItem
 import android.view.View
 import android.widget.*
 import androidx.appcompat.app.AppCompatActivity
-import androidx.appcompat.app.AppCompatDelegate
+import androidx.preference.PreferenceManager
 import fr.corenting.convertisseureurofranc.convert.ConvertAbstract
 import fr.corenting.convertisseureurofranc.convert.France
 import fr.corenting.convertisseureurofranc.convert.USA
 import fr.corenting.convertisseureurofranc.utils.Utils
 import kotlinx.android.synthetic.main.activity_converter.*
-import java.util.*
 
 class ConverterActivity : AppCompatActivity() {
 
@@ -25,10 +23,9 @@ class ConverterActivity : AppCompatActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         // Dark theme
         prefs = PreferenceManager.getDefaultSharedPreferences(this)
-        if (prefs.getBoolean(getString(R.string.preferenceDarkThemeKey), false)) {
-            AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES)
-        } else {
-            AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO)
+        when {
+            prefs.getBoolean(getString(R.string.preferenceDarkThemeKey), false) -> setTheme(R.style.AppThemeDark)
+            else -> setTheme(R.style.AppTheme)
         }
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_converter)
@@ -41,8 +38,8 @@ class ConverterActivity : AppCompatActivity() {
         initButtons()
 
         //Set currency spinner content
-        val currenciesList = Arrays
-                .asList(getString(R.string.france_currencies), getString(R.string.usa_currencies))
+        val currenciesList = listOf(getString(R.string.france_currencies),
+                getString(R.string.usa_currencies))
         setSpinnerAdapter(currencySpinner, currenciesList)
         currencySpinner.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
             override fun onItemSelected(parent: AdapterView<*>?, view: View?, pos: Int, id: Long) {
@@ -82,14 +79,15 @@ class ConverterActivity : AppCompatActivity() {
 
     private fun initSpinners() {
         //Populate the spinners with a list of years
-        val yearsList = (converter.latestYear downTo converter.firstYear)
-                .mapTo(LinkedList()) { it.toString() }
-        setSpinnerAdapter(yearOfOriginSpinner!!, yearsList)
-        setSpinnerAdapter(yearOfResultSpinner!!, yearsList)
+        val yearsList = (converter.latestYear downTo converter.firstYear).toList().map {
+            it.toString()
+        }
+        setSpinnerAdapter(yearOfOriginSpinner, yearsList)
+        setSpinnerAdapter(yearOfResultSpinner, yearsList)
 
         //Add an onItemSelected listener to change the currency text according to the year
-        setSpinnerListener(yearOfOriginSpinner!!, currencyOriginTextView)
-        setSpinnerListener(yearOfResultSpinner!!, currencyResultTextView)
+        setSpinnerListener(yearOfOriginSpinner, currencyOriginTextView)
+        setSpinnerListener(yearOfResultSpinner, currencyResultTextView)
     }
 
     private fun initButtons() {
@@ -100,7 +98,7 @@ class ConverterActivity : AppCompatActivity() {
         //Click button when using enter on the keyboard
         amountEditText.setOnKeyListener(View.OnKeyListener { _, _, event ->
             if (event.action == KeyEvent.ACTION_DOWN && event.keyCode == KeyEvent.KEYCODE_ENTER) {
-                convertButton!!.performClick()
+                convertButton.performClick()
                 return@OnKeyListener false
             }
             false
@@ -131,12 +129,12 @@ class ConverterActivity : AppCompatActivity() {
         s.adapter = adapter
     }
 
-    private fun setSpinnerListener(spinner: Spinner, textView: TextView?) {
+    private fun setSpinnerListener(spinner: Spinner, textView: TextView) {
         spinner.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
             override fun onItemSelected(parent: AdapterView<*>?, view: View?, pos: Int, id: Long) {
                 if (parent != null) {
                     val year = Integer.parseInt(parent.getItemAtPosition(pos).toString())
-                    textView!!.text = converter.getCurrencyFromYear(year)
+                    textView.text = converter.getCurrencyFromYear(year)
                 }
             }
 
diff --git a/app/src/main/res/layout/activity_converter.xml b/app/src/main/res/layout/activity_converter.xml
index aba7c5d..e5d4f77 100644
--- a/app/src/main/res/layout/activity_converter.xml
+++ b/app/src/main/res/layout/activity_converter.xml
@@ -1,7 +1,8 @@
 <ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
     android:id="@+id/scrollView"
     android:layout_width="wrap_content"
-    android:layout_height="wrap_content">
+    android:layout_height="wrap_content"
+    >
 
     <RelativeLayout
         android:layout_width="wrap_content"
@@ -16,7 +17,7 @@
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="@string/currency"
-            android:textAppearance="?android:attr/textAppearanceMedium" />
+            android:textAppearance="@style/TextAppearance.MaterialComponents.Body1" />
 
         <Spinner
             android:id="@+id/currencySpinner"
@@ -38,7 +39,7 @@
             android:layout_below="@+id/currencyTextView"
             android:layout_marginTop="12dp"
             android:text="@string/sumToConvert"
-            android:textAppearance="?android:attr/textAppearanceMedium" />
+            android:textAppearance="@style/TextAppearance.AppCompat.Body1" />
 
         <EditText
             android:id="@+id/amountEditText"
@@ -68,7 +69,7 @@
             android:layout_below="@id/currencyOriginTextView"
             android:layout_alignBaseline="@+id/yearOfOriginSpinner"
             android:text="@string/yearOfOrigin"
-            android:textAppearance="?android:attr/textAppearanceSmall" />
+            android:textAppearance="@style/TextAppearance.AppCompat.Body1" />
 
         <Spinner
             android:id="@+id/yearOfOriginSpinner"
@@ -90,7 +91,7 @@
             android:layout_alignParentStart="true"
             android:layout_alignParentLeft="true"
             android:text="@string/yearOfResult"
-            android:textAppearance="?android:attr/textAppearanceSmall" />
+            android:textAppearance="@style/TextAppearance.AppCompat.Body1" />
 
         <Spinner
             android:id="@+id/yearOfResultSpinner"
@@ -121,7 +122,7 @@
             android:layout_alignParentLeft="true"
             android:layout_marginTop="24dp"
             android:text="@string/resultText"
-            android:textAppearance="?android:attr/textAppearanceMedium" />
+            android:textAppearance="@style/TextAppearance.AppCompat.Body1" />
 
         <EditText
             android:id="@+id/resultEditText"
diff --git a/app/src/main/res/values/colors.xml b/app/src/main/res/values/colors.xml
index 93af93f..c5b8d38 100644
--- a/app/src/main/res/values/colors.xml
+++ b/app/src/main/res/values/colors.xml
@@ -3,4 +3,9 @@
     <item name="colorPrimary" type="color">#03a9f4</item>
     <item name="colorPrimaryDark" type="color">#0288d1</item>
     <item name="colorAccent" type="color">#448AFF</item>
+
+    <color name="darkPrimary">#ff607d8b</color>
+    <color name="darkPrimaryDark">#ff455a64</color>
+    <color name="darkAccent">#ffff5252</color>
+
 </resources>
\ No newline at end of file
diff --git a/app/src/main/res/values/styles.xml b/app/src/main/res/values/styles.xml
index 00aa3e6..f50bfb3 100644
--- a/app/src/main/res/values/styles.xml
+++ b/app/src/main/res/values/styles.xml
@@ -1,7 +1,19 @@
 <resources>
-    <style name="AppTheme" parent="Theme.MaterialComponents.DayNight.DarkActionBar">
+
+    <style name="AppTheme" parent="Theme.MaterialComponents.Light.DarkActionBar">
         <item name="colorPrimary">@color/colorPrimary</item>
         <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
         <item name="colorAccent">@color/colorAccent</item>
     </style>
+
+    <style name="AppThemeDark" parent="Theme.MaterialComponents">
+        <item name="colorPrimary">@color/darkPrimary</item>
+        <item name="colorPrimaryDark">@color/darkPrimaryDark</item>
+        <item name="colorAccent">@color/darkAccent</item>
+        <item name="actionBarTheme">@style/AppThemeDarkActionBar</item>
+    </style>
+
+    <style name="AppThemeDarkActionBar" parent="@style/ThemeOverlay.AppCompat.Dark.ActionBar">
+        <item name="popupTheme">@style/ThemeOverlay.AppCompat.Light</item>
+    </style>
 </resources>
\ No newline at end of file
diff --git a/build.gradle b/build.gradle
index 3ca9435..6834921 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,13 +1,13 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
-    ext.kotlin_version = '1.3.21'
+    ext.kotlin_version = '1.3.31'
     repositories {
         jcenter()
         google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.3.1'
+        classpath 'com.android.tools.build:gradle:3.4.2'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
 
         // NOTE: Do not place your application dependencies here; they belong
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 92f8868..096f492 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Tue Feb 12 17:32:37 CET 2019
+#Mon Jul 15 22:20:38 CEST 2019
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.1.1-all.zip