session-android/res/layout/conversation_list_fragment.xml

<?xml version="1.0" encoding="utf-8"?>

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
              xmlns:tools="http://schemas.android.com/tools"
              xmlns:fab="http://schemas.android.com/apk/res-auto"
              android:layout_width="fill_parent"
              android:layout_height="fill_parent"
              android:orientation="vertical">

        <ListView android:id="@android:id/list"
                  android:layout_width="fill_parent"
                  android:layout_height="match_parent"
                  android:drawSelectorOnTop="false"
                  android:scrollbarStyle="insideOverlay"
                  android:fadingEdgeLength="16dip"
                  android:divider="?conversation_list_item_divider"
                  android:headerDividersEnabled="false"
                  android:footerDividersEnabled="false"
                  android:dividerHeight="1px"
                  tools:listitem="@layout/conversation_list_item_view"/>

    <com.melnykov.fab.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|right"
        android:layout_margin="16dp"
        android:src="@drawable/ic_add_white_24dp"
        fab:fab_colorNormal="?fab_color"
        fab:fab_colorPressed="@color/textsecure_primary_dark"
        fab:fab_colorRipple="@color/textsecure_primary_dark" />

</FrameLayout>