I've never used this "app" but this "Holster Hunter" is thanks to my local gun store's website, but it should give you an idea on what's available. You just enter your manufacturer, model/barrel size, and if it has any accessories. Click "Find my holster" and it should then give you a list. Granted, it's probably only a list of what that store carries, but maybe it'll give you a starting point.
http://www.officerstore.com/store/holst ... intro.aspx