<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="vertical"
              android:layout_width="fill_parent"
              android:layout_height="fill_parent"
        >
    <TextView
            android:id="@id/balanceView"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:textSize="48sp"
            android:paddingBottom="48sp"
            />
    <Button
            android:id="@+id/refreshBalanceButton"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/update_balance_button"
            android:drawableTop="@android:drawable/ic_popup_sync"
            android:layout_gravity="center_horizontal"/>
</LinearLayout>


<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="vertical"
              android:layout_width="fill_parent"
              android:layout_height="fill_parent"
              android:gravity="center"
              android:layout_weight="2"
        >
    <TextView
            android:id="@id/balanceView"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:textSize="72sp"
            android:paddingBottom="48sp"
            android:layout_weight="2"
            />
    <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="0dip"
            android:gravity="center|bottom"
            android:layout_weight="1">

        <Button
                android:id="@+id/refreshBalanceButton"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                style="?android:attr/buttonStyle"
                android:text="@string/update_balance_button"
                android:drawableTop="@android:drawable/ic_popup_sync"
                />
    </LinearLayout>
</LinearLayout>


Put update button at bottom and text more centered
Put update button at bottom and text more centered
