I want to draw
Look at my answer here for widgets/app.
You can use shapecount.xml
res/layout/tabicon.xml
android:layout_margin="0dp"
android:layout_height="wrap_content"
android:layout_width="wrap_content"/>
When creating your tab:
LayoutInflater inflater = LayoutInflater.from(this);
View view = inflater.inflate(R.layout.tabicon, null);
final TextView txtCount = (TextView) view.findViewById(R.id.txtCount);
spec = tabHost.newTabSpec("artists").setIndicator(view).setContent(intent);
Now you can use txtCount to update the number in the tab's icon. See the post I pointed out above for an example of TimerTask to test this.
You will have to arrange the layout as you wish also