Knowing what name to display isn't always enough - you also need to think about how the rest of the text around it should be translated to match. For German, the safe answer is still third-person plural Sie, unless you're absolutely certain your audience are all children, and missing that distinction might be taken by your audience as either that you're trying to be creepily over-familiar, or that you think they're children.
A sibling comment says that "Du" (second-person familiar) for business is becoming more common, and while that's true, I would NOT recommend using it without a good knowledge of German culture and your specific audience.