In the search results the acronym YSA means Young Single Adult and is a branch or ward for those who are single and between the ages of 18 and 30. Listings that say "student single" are the same as YSA except regular worshipers also have to be students of the local university/college. Visitors are always welcome to worship with us, so feel free to find a LDS Church building near you as well as the time of worship, who the bishop is, and even directions on how to get there.
Thanks to LDS Media Talk (previously LDSWebGuy) for this news. Their blog post, "New Meetinghouse Locator on LDS.org - Beta Release" also gives a list of the new features available with this application.