WordPress/src/main/res/layout/tab_icon.xml

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

<!--
    Custom view used when showing icons in main activity's tab layout
-->
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="wrap_content"
    android:layout_height="@dimen/toolbar_height"
    android:paddingLeft="@dimen/tabstrip_icon_spacing"
    android:paddingRight="@dimen/tabstrip_icon_spacing"
    tools:background="@color/color_primary">

    <ImageView
        android:id="@+id/tab_icon"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        tools:src="@drawable/main_tab_notifications" />

    <View
        android:id="@+id/tab_badge"
        android:layout_width="16dp"
        android:layout_height="16dp"
        android:layout_gravity="center"
        android:layout_marginLeft="-8dp"
        android:layout_marginTop="-8dp"
        android:background="@drawable/badge"
        android:visibility="gone"
        tools:visibility="visible" />

</FrameLayout>