session-android/res/layout/device_list_fragment.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:fab="http://schemas.android.com/apk/res-auto">

    <ProgressBar
        android:id="@+id/activityIndicator"
        android:indeterminate="true"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:visibility="gone" />

    <TextView
        android:id="@+id/emptyStateTextView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center"
        android:textSize="20sp"
        android:visibility="gone"
        android:text="@string/device_list_fragment__no_devices_linked"
        android:paddingStart="16dip"
        android:paddingEnd="16dip"
        tools:visibility="visible"/>

    <ListView
        android:id="@id/android:list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:drawSelectorOnTop="false" />

    <com.melnykov.fab.FloatingActionButton
        android:id="@+id/addDeviceButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentRight="true"
        android:layout_margin="16dp"
        android:src="@drawable/ic_add_white_original_24dp"
        android:focusable="true"
        android:contentDescription="@string/device_list_fragment__link_new_device"
        fab:fab_colorNormal="?fab_color"
        fab:fab_colorPressed="@color/textsecure_primary_dark"
        fab:fab_colorRipple="@color/textsecure_primary_dark" />

</RelativeLayout>