activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context="fr.utc.simde.payutc.MainActivity"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:gravity="center"
        android:orientation="vertical"
        android:layout_alignParentTop="true"
        android:layout_alignParentStart="true">

        <ImageView
            android:id="@+id/img_payutc"
            android:layout_width="100dp"
            android:layout_height="100dp"
            android:layout_marginBottom="10dp"
            android:contentDescription="@string/app_name"
            android:src="@mipmap/ic_launcher_round" />

        <TextView
            android:id="@+id/text_app_name"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:text="@string/app_name"
            android:textSize="24dp"
            android:textStyle="bold" />

        <TextView
            android:id="@+id/text_app_config"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="50dp"
            android:gravity="center"
            android:textSize="18dp"
            android:textStyle="bold" />
        <TextView
            android:id="@+id/text_hello"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:gravity="center"
            android:text="@string/hello" />

        <Button
            android:id="@+id/button_username"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginBottom="100dp"
            android:text="@string/connect" />

    </LinearLayout>

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:layout_alignParentBottom="true" >

        <TextView
            android:id="@+id/text_app_registered"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:textStyle="italic"
            android:text="@string/app_not_registred" />

        <TextView
            android:id="@+id/text_author"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="@string/author"
            android:layout_marginBottom="10dp"
            android:gravity="center" />
    </LinearLayout>

</RelativeLayout>