Hi Enrico,
You have to add some OutlookBarGroups to the OutlookBar and you can use any controls to specify the content and header of each group. For example:
<ig:XamOutlookBar>
  <ig:OutlookBarGroup Header="UserControl Content">
    <local:TileViewSimple x:Name="userControl"/>
    <ig:OutlookBarGroup.LargeIconTemplate>
      <DataTemplate>
        <StackPanel Orientation="Horizontal">
          <Ellipse Fill="Green" Stroke="Black" Width="10" Height="10" Margin="4,0,0,0"/>
        </StackPanel>
      </DataTemplate>
    </ig:OutlookBarGroup.LargeIconTemplate>
  </ig:OutlookBarGroup>
  <ig:OutlookBarGroup>
    <ig:OutlookBarGroup.HeaderTemplate>
      <DataTemplate>
        <StackPanel Orientation="Horizontal">
          <TextBlock Text="Custom Header" Foreground="Blue"/>
        </StackPanel>
      </DataTemplate>
    </ig:OutlookBarGroup.HeaderTemplate>
    <ig:OutlookBarGroup.LargeIconTemplate>
      <DataTemplate>
        <StackPanel Orientation="Horizontal">
          <Ellipse Fill="Gold" Stroke="Black" Width="10" Height="10" Margin="4,0,0,0"/>
        </StackPanel>
      </DataTemplate>
    </ig:OutlookBarGroup.LargeIconTemplate>
    <Grid>
      <ig:XamMenu VerticalAlignment="Top">
        <ig:XamMenuItem Header="File">
          <ig:XamMenuItem Header="Open"/>
        </ig:XamMenuItem>
      </ig:XamMenu>
    </Grid>
  </ig:OutlookBarGroup>
</ig:XamOutlookBar>

Regards,
Marin