activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#4B4B4B"
    tools:context=".MainActivity">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_margin="10dp"
        android:background="#EDE3D6">
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">
            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="80dp"
                android:orientation="horizontal">
                <TextView
                    android:layout_width="125dp"
                    android:layout_height="80dp"
                    android:textSize="40dp"
                    android:text="Name:"/>

                <EditText
                    android:id="@+id/username"
                    android:layout_width="180dp"
                    android:layout_height="80dp"
                    android:textSize="40dp"
                     />
                <ImageButton
                    android:id="@+id/confirmUsername"
                    android:layout_width="80dp"
                    android:layout_height="80dp"
                    android:src="@drawable/tick"
                    android:scaleType="fitCenter"
                    android:adjustViewBounds="true"
                    />
            </LinearLayout>
            <TextView
                android:layout_width="match_parent"
                android:layout_height="2dp"
                android:background="#696A62"/>
        </LinearLayout>
        <TextView
            android:id="@+id/displayText"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_marginTop="100dp"
            android:layout_marginBottom="120dp" />

        <ImageButton
            android:layout_width="100dp"
            android:layout_height="100dp"
            android:id="@+id/onRecord"
            android:layout_alignParentBottom="true"
            android:layout_marginBottom="6dp"
            android:layout_centerInParent="true"
            android:id="@+id/onRecord"
            android:background="#696A62"
            android:scaleType="fitCenter"
            android:adjustViewBounds="true"
            android:src="@drawable/microphone_icon" />
    </RelativeLayout>

</android.support.constraint.ConstraintLayout>