a static (hopefully final) instance variable consitutes a type of singleton (ok, for a real singleton you'd also need to take steps to ensure that the instance class is not instantiated otherwise). This in itself is not bad. It may (or may not) convey that this class should only be used through the instance Tutuapp.

I have noticed that some sites - mostly fanfiction or other heavily text-based but low-budget websites - replace some text with black diamonds with question marks in them.