Do you need automatic seating or a spreadsheet
Four questions: keep-aparts, plus-ones, whole groups, guest count. Two yeses and a spreadsheet will fight you.
Wedding seating chart app or Excel?
Excel or WeddingWire is enough when nobody must be kept apart and the list is done. Keep-aparts, unnamed plus-ones, and groups that must stay whole are when you want automatic seating that can reseat.