diff --git a/.idea/.name b/.idea/.name
new file mode 100644
index 0000000..d6b401b
--- /dev/null
+++ b/.idea/.name
@@ -0,0 +1 @@
+AndroidFundamentalsMay2021
\ No newline at end of file
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 40ca0af..02a3d89 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -11,10 +11,7 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/Theme.AndroidFundamentalsMai2021">
-        <activity android:name=".ConstraintLayoutSampleActivity"></activity>
-        <activity android:name=".MainActivity" />
-        <activity android:name=".EmailsActivity" />
-        <activity android:name=".StartActivity">
+        <activity android:name=".MainActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
 
diff --git a/app/src/main/java/com/magdamiu/androidfundamentalsmai2021/MainActivity.java b/app/src/main/java/com/magdamiu/androidfundamentalsmai2021/MainActivity.java
index fcf6fcb..d70ee3f 100644
--- a/app/src/main/java/com/magdamiu/androidfundamentalsmai2021/MainActivity.java
+++ b/app/src/main/java/com/magdamiu/androidfundamentalsmai2021/MainActivity.java
@@ -1,131 +1,13 @@
 package com.magdamiu.androidfundamentalsmai2021;
 
-import androidx.appcompat.app.AppCompatActivity;
-
 import android.os.Bundle;
-import android.util.Log;
-import android.view.View;
-import android.webkit.WebView;
-import android.widget.AdapterView;
-import android.widget.ArrayAdapter;
-import android.widget.Button;
-import android.widget.EditText;
-import android.widget.Spinner;
-import android.widget.TextView;
-import android.widget.Toast;
 
-import java.util.ArrayList;
-import java.util.List;
+import androidx.appcompat.app.AppCompatActivity;
 
 public class MainActivity extends AppCompatActivity {
-    private static final String ANDROID_URL = "https://developer.android.com/";
-
-    private EditText editTextName;
-    private Button buttonDisplayGreetings;
-    private TextView textViewGreetings;
-
-    private WebView webView;
-
-    private Spinner spinnerAndroidVersions;
-    private List<String> androidVersions;
-    private ArrayAdapter<String> spinnerAdapter;
-
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        /*setContentView(R.layout.activity_main);*/
-        /*setContentView(R.layout.sample);*/
-        // setContentView(R.layout.scrollview_sample);
-        // setContentView(R.layout.webview_sample);
-        setContentView(R.layout.week3_code_challenge_2);
-
-    /*    setAndroidVersions();
-        initialiseSpinnerAdapter();
-        setSpinnerAdapter();
-        handlingSpinnerListener();*/
-
-        //loadUrl();
-
-        // initViews();
-        displayLogs();
-    }
-
-    // step 1: data source for our spinner
-    private void setAndroidVersions() {
-        androidVersions = new ArrayList<>();
-        androidVersions.add("cupcake");
-        androidVersions.add("eclair");
-        androidVersions.add("pie");
-        androidVersions.add("donut");
-        androidVersions.add("kitkat");
-    }
-
-    // step 2: initialise adapter for our spinner
-    // ArrayAdapter is a default adapter
-    private void initialiseSpinnerAdapter() {
-        spinnerAdapter = new ArrayAdapter<>(MainActivity.this,
-                android.R.layout.simple_spinner_item,
-                androidVersions);
-    }
-
-    // step 3: set the adapter to our spinner
-    private void setSpinnerAdapter() {
-        spinnerAndroidVersions = findViewById(R.id.spinnerAndroidVersions);
-        spinnerAndroidVersions.setAdapter(spinnerAdapter);
-    }
-
-    private void handlingSpinnerListener() {
-        spinnerAndroidVersions.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
-            @Override
-            public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
-                String selectedAndroidVersion = androidVersions.get(i);
-                Toast.makeText(MainActivity.this, selectedAndroidVersion, Toast.LENGTH_LONG).show();
-            }
-
-            @Override
-            public void onNothingSelected(AdapterView<?> adapterView) {
-
-            }
-        });
-    }
-
-    // webview load url
-    private void loadUrl() {
-        webView = findViewById(R.id.webViewSample);
-        webView.getSettings().setJavaScriptEnabled(true);
-        webView.loadUrl(ANDROID_URL);
-    }
-
-    // init views for implementing a first simple form
-    private void initViews() {
-        editTextName = findViewById(R.id.editTextName);
-        buttonDisplayGreetings = findViewById(R.id.buttonDisplayGreetings);
-        textViewGreetings = findViewById(R.id.textViewGreetings);
-    }
-
-    private void displayLogs() {
-        Log.e("tag-error", "my first error log");
-        Log.v("tag-verbose", "my first verbose log");
-        Log.w("tag-warning", "my first warning log");
-    }
-
-    private void clickOnDisplayGreetingsButton() {
-        buttonDisplayGreetings.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View view) {
-
-            }
-        });
-    }
-
-    public void displayGreetingsOnClick(View view) {
-        textViewGreetings.setText("");
-        String inputName = editTextName.getText().toString();
-        if (inputName.length() > 0) {
-            textViewGreetings.setText(inputName);
-        } else {
-            editTextName.setError(getString(R.string.error_insert_name));
-            Toast.makeText(MainActivity.this, getString(R.string.error_insert_name), Toast.LENGTH_LONG).show();
-        }
+        setContentView(R.layout.course4_code_challenge_1);
     }
 }
\ No newline at end of file
diff --git a/app/src/main/res/drawable/android_1.png b/app/src/main/res/drawable/android_1.png
new file mode 100644
index 0000000..9f4d206
Binary files /dev/null and b/app/src/main/res/drawable/android_1.png differ
diff --git a/app/src/main/res/drawable/android_2.png b/app/src/main/res/drawable/android_2.png
new file mode 100644
index 0000000..5f7b9f4
Binary files /dev/null and b/app/src/main/res/drawable/android_2.png differ
diff --git a/app/src/main/res/drawable/android_3.png b/app/src/main/res/drawable/android_3.png
new file mode 100644
index 0000000..1055062
Binary files /dev/null and b/app/src/main/res/drawable/android_3.png differ
diff --git a/app/src/main/res/drawable/android_logo.png b/app/src/main/res/drawable/android_logo.png
index 7ce5aa1..e69de29 100644
Binary files a/app/src/main/res/drawable/android_logo.png and b/app/src/main/res/drawable/android_logo.png differ
diff --git a/app/src/main/res/drawable/robot.png b/app/src/main/res/drawable/robot.png
index 15aa5a7..e69de29 100644
Binary files a/app/src/main/res/drawable/robot.png and b/app/src/main/res/drawable/robot.png differ
diff --git a/app/src/main/res/layout/course4_code_challenge_1.xml b/app/src/main/res/layout/course4_code_challenge_1.xml
new file mode 100644
index 0000000..06e42cf
--- /dev/null
+++ b/app/src/main/res/layout/course4_code_challenge_1.xml
@@ -0,0 +1,70 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:orientation="vertical">
+
+    <RelativeLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:background="@color/light_beige">
+
+        <ImageView
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_alignParentStart="true"
+            android:src="@drawable/android_1" />
+
+        <ImageView
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_alignParentEnd="true"
+            android:layout_margin="8dp"
+            android:src="@drawable/android_2" />
+
+    </RelativeLayout>
+
+    <View
+        android:layout_width="match_parent"
+        android:layout_height="@dimen/space_2"
+        android:background="@color/black" />
+
+    <FrameLayout
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
+        <TextView
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:layout_gravity="center"
+            android:background="@color/light_green" />
+
+        <TextView
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:layout_gravity="center"
+            android:layout_margin="@dimen/space_16"
+            android:background="@color/dark_green" />
+
+        <TextView
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:layout_gravity="center"
+            android:layout_margin="@dimen/space_32"
+            android:background="@color/dark_pink" />
+
+        <TextView
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:layout_gravity="center"
+            android:layout_margin="@dimen/space_48"
+            android:background="@color/light_beige" />
+
+        <ImageView
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_gravity="center"
+            android:src="@drawable/android_3" />
+    </FrameLayout>
+
+</LinearLayout>
\ No newline at end of file
diff --git a/app/src/main/res/values/colors.xml b/app/src/main/res/values/colors.xml
index d8ce349..d78f50a 100644
--- a/app/src/main/res/values/colors.xml
+++ b/app/src/main/res/values/colors.xml
@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
+    <color name="light_green">#90ee90</color>
+    <color name="dark_green">#006400</color>
+    <color name="dark_pink">#c30082</color>
+    <color name="light_beige">#F5F5DD</color>
     <color name="purple_200">#FFBB86FC</color>
     <color name="purple_500">#FF6200EE</color>
     <color name="purple_700">#FF3700B3</color>
diff --git a/app/src/main/res/values/dimens.xml b/app/src/main/res/values/dimens.xml
index e8b2c28..832639e 100644
--- a/app/src/main/res/values/dimens.xml
+++ b/app/src/main/res/values/dimens.xml
@@ -4,4 +4,8 @@
     <dimen name="medium_space">16dp</dimen>
     <dimen name="space_128">128dp</dimen>
     <dimen name="space_64">64dp</dimen>
+    <dimen name="space_2">2dp</dimen>
+    <dimen name="space_16">16dp</dimen>
+    <dimen name="space_32">32dp</dimen>
+    <dimen name="space_48">48dp</dimen>
 </resources>
\ No newline at end of file
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index b363a5c..693b9c8 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -1,5 +1,5 @@
 <resources>
-    <string name="app_name">Curs Android Fundamentals</string>
+    <string name="app_name">ViewGroups Example</string>
     <string name="hello_world_from_android">Hello World from Android!</string>
     <string name="this_is_my_first_textview">This is my first TextView</string>
     <string name="i_am_a_button">I am a button</string>