Rated 5 out of 5 stars

I had tried the Add-on 'Track Package', but that failed within an hour of installation so I searched for an alternative. I then found this Add-on, installed it and restarted FF. Thus far, I am quite satisfied. If it continues to work as it has initially I will be delighted as it is incredibly useful if you need to track many packages. I will use this for a few days and report any problems or idiosyncrasies.