This is an example of How to add a badge in tab

chat_tab.xml

<RelativeLayout xmlns:android='http://schemas./apk/res/android'    android:layout_width='0dip'     android:layout_height='64dip'    android:layout_weight='1'     android:layout_marginLeft='-3dip'     android:layout_marginRight='-3dip'     android:orientation='vertical'     android:background='@drawable/tab_indicator' >    <ImageView        android:id='@+id/chat_icon'        android:layout_width='wrap_content'        android:layout_height='wrap_content'        android:src='@drawable/chat_icon'        android:layout_centerHorizontal='true'/>    <TextView        android:id='@+id/new_notifications'         android:layout_width='wrap_content'        android:layout_height='wrap_content'        android:layout_alignTop='@+id/chat_icon'        android:layout_toRightOf='@+id/chat_icon'        android:layout_marginLeft='-8dp'        android:layout_marginTop='0dp'        android:paddingTop='2dp'        android:paddingLeft='5dp'        android:paddingRight='5dp'        android:paddingBottom='2dp'        android:textSize='8sp'        android:textStyle='bold'        android:textColor='@android:color/primary_text_dark'        android:background='@drawable/badge'        android:visibility='gone'/>    <TextView         android:layout_width='wrap_content'        android:layout_height='wrap_content'        android:text='@string/chat'        style='@android:attr/tabWidgetStyle'        android:textColor='@android:color/tab_indicator_text'        android:layout_centerHorizontal='true'        android:layout_alignParentBottom='true'/></RelativeLayout>

This is badge.xml (red circle for notifications background), TextView id:new_notifications background

<?xml version='1.0' encoding='utf-8'?><shape xmlns:android='http://schemas./apk/res/android'       android:shape='oval' >    <stroke android:width='2dp' android:color='#FFFFFF' />    <corners android:radius='10dp'/>    <padding android:left='2dp' />    <solid android:color='#ff2233'/></shape>

Then in the code you can simply do

LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);View chatTab = inflater.inflate(R.layout.chat_tab, null);tvNewNotifications = (TextView) chatTab.findViewById(R.id.new_notifications);intent = new Intent().setClass(MainTab.this, Chat.class);tabSpec = tabHost            .newTabSpec('chat')            .setIndicator(chatTab)            .setContent(intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP));

As you can see my Relative Layout has a background @drawable/tab_indicator the tab indicator.xml is the framework's standard drawable of the tab,which i got from the sdk,i suggest you should also get it from the folder of the api in sdk as you also need to copy some images from the drawable folders,you can find it your_sdk_drive:\sdk\platforms\android-8