The Trial RosterSMS Roster Change Alert service has been running for 9 months now. The trial has massively overrun it's original planned time due to other commitments.
Now that I have experience running the system over a reasonable number of bid periods I have enough data to predict costs. I can also see the major hole in the bank account from running the system.
So, this is the long way of saying that the Roster Change Alert trial is complete. It is being replaced with a separate service called Unnotified Duties Alert. I am hoping you will find it useful. You can subscribe by following the link: https://rostersms.com/product/unnotified-duties-alert/
NOTE: When you have unnotified duties on your roster, RosterSMS Calendar cannot be updated until you accept those duties.