Necessity is the mother of invention. That is the indeed case here, and I think it's a wonderful idea.

TopBucks Mobile sure knows how to attract good attention by offering a free event guide apps for the upcoming Mobile Show Guide trade show. By downloading the apps on one's smartphone, attendees will get schedules of events as well as other activities being staged during the event. This is not only a very convenient way to plan one's event itinerary, it is also a good calling card for TopBucks to show how they work. To receive the free apps, attendees must submit their phone numbers through SMS.