Nearly six months after launching Paper for iPad to much praise and fanfare , George Petschnigg still can’t stop smiling. Our interview hasn’t even begun and he’s already spouting off the various ways his team has tightened up Paper to be easier and more intuitive for users. It’s typical startup founder talk, except Petschnigg leads an unusual startup that has thus far delivered on its promises to build a great product. Ask him about money, and his tail drops between his legs as if he’s ashamed, or perhaps even embarrassed, for profiting on a tool he built for himself, his friends, and his colleagues. His company, FiftyThree , is now thirteen employees strong, but still largely works out of Petschnigg’s one-bedroom apartment in TriBeCa,..