Navigon POI will allow you to create a set of Custom POI 's from scratch.
Silverlight Inspector is a utility for inspecting Silverlight XAP files.
PandaZune can let Windows phone users search the Pandaapp Marketplace app.
xScript is a scripting engine for xAP and xPL with both protocols in a place.
A DirectShow-based application which allows you playing Silverlight xap apps.
This add-in provides a simple "Save As" option within PowerPoint 2007.