Yapp is a service that allows the average person to create a professional-looking mobile app for events such as weddings, birthday parties, book club meetings, reunions, fundraisers, retreats, etc. It integrates with many of the features of the mobile device, allowing messaging, maps/directions to the event, photo sharing, etc. Once you create the app for your event, it can be shared with others after they install the YappBox app. Looks like a pretty nifty tool, and it’s free (they make money by offering premium services for a fee).
Thanks to Donna for this link.