I did consider writing a rostering/scheduling app as a follow on to PerfectTablePlan. But it seems to me that the constraints vary wildly from one organization/market to the next. Making it very hard to create an 'off the shelf' package that is general enough to be useful while simple enough to be useable.
Not the person you replied to, but have been studying rostering the last few months out of curiosity. What does the rostering app you currently use (if any) do wrong and what would make it better for you?
PerfectTablePlan: Event seating plans.
Hyper Plan: Visual task planner.
Easy Data Transform: Data wrangling.