HN review will give you a good sense of how useful your “fancy” application is, this is paramount to whatever promotion you may want to take your product into. Good review on HN gives you a strong launch pad, I speak from experience. You may get meaningful coverage over the internet, better than what mass mailing, spam posting and any other free platform will do.

Other alternatives are places like techcrunch ; there you must be one in the circle or getting a funding scoop. Or at best they will write in an effort to bury you instead. :-)