<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:orientation="vertical" >

    <Button
        android:id="@+id/send"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Mark an event" />

    <Button
        android:id="@+id/upgrade"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Level upgrade" />

    <Button
        android:id="@+id/purchase"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Purchase" />

</LinearLayout>