Package Designer works well and is easy to use. It provides easy scaffolding for packages and the integration with Block Designer is a real time saver. I think this add-on could be saving even more time, e.g. by fixing wrong icon images (border-radius) or giving icon suggestions from a free service based on the package name or description. Also maybe the list of package versions might be retrieved from an external page? This to prevent you having to update the add-on each time a new C5 version is released? Overall, a nice and handy plugin for developers!