What a great plugin!
I tried to log in to their site to tell them about a database problem though, and apparently they don't want that sort of feedback except from paid subscribers.
The database wp_wfStatus has no primary key, and it really ought to. This causes problems for some other plugins that perform mass database operations, especially operations like renaming your wordpress site to a different domain or such.
I imagine this will be fixed soon, since it's such an easy thing to do.