from https://classroom.udacity.com/nanodegrees/ Android developer. We create the code for a simple app

first android app #XML code

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="16dp"
    android:paddingRight="16dp"
    android:paddingTop="16dp"
    android:paddingBottom="16dp"
    android:orientation="vertical">

    <ImageView
        android:src="@drawable/ocean"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:scaleType="centerCrop"
        android:layout_marginBottom="8dp" />

    <TextView
        android:text="You're invited!"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="@android:color/white"
        android:textSize="45sp"
        android:background="#009688"/>

    <TextView
        android:text="Bonfire at the beach"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="@android:color/white"
        android:textSize="24sp"
        android:background="#009688"/>

</LinearLayout>