The women-centric app Lulu is a database that features women's reviews of men they know or have dated. For men, no such database exists as of 2015.
Lulu provides a rating system that allows women to publicize whether a man is a "good catch," or is "cheap as a Big Mac," among other warnings.The crowd-sourced review system gives each man a numerical rating, indicating how desirable he may be to date. As of 2015, the app was only available to women, although a separate app was available that allowed men to see their ratings.
While many resources exist about types of women or even first names of women to avoid dating, there is no database of undatable women.