With the DOM Inspector you can browse the document object model of your XUL pages. It is especially helpful when you are developing themes. With this tool you can easily find out what styles are applied to certain elements or find the problem when elements aren't rendered how they are supposed to.
Before you start here please install the Debug menu first, you will need the Add-ons functionality.
First download the dom-inspector.xpi by clicking on the download link below. When you are done with that go to the Debug menu and click Add-ons. The add-ons screen appears with a list of all currently installed add-ons. In this screen click Install... and select the dom-inspector.xpi. After yu click OK, TomTom HOME will install the extension and ask you to restart TomTom HOME. After restarting the application the DOM Inspector will be installed.