session-android/res/layout/activity_home.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"
    android:background="@drawable/default_session_background">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <!-- The button below intentionally uses dp for the text size and not sp -->

    <RelativeLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_alignParentBottom="true"
        android:layout_marginBottom="@dimen/new_conversation_button_bottom_offset">

        <View
            android:layout_width="72dp"
            android:layout_height="72dp"
            android:background="@drawable/new_conversation_button_background" />

        <Button
            android:id="@+id/newConversationButton"
            android:layout_width="@dimen/new_conversation_button_size"
            android:layout_height="@dimen/new_conversation_button_size"
            android:layout_centerInParent="true"
            android:paddingLeft="1dp"
            android:paddingBottom="2dp"
            android:background="@drawable/new_conversation_button_foreground"
            android:fontFamily="@font/roboto_light"
            android:textSize="40dp"
            android:textColor="#121212"
            android:text="+"
            android:elevation="0dp"
            android:stateListAnimator="@null" />

    </RelativeLayout>

</RelativeLayout>