Are you in the United States? you might want to consider forming a shell corporation. As long as you are willing to disclose all receipts and pay all taxes, you should be fine. Don't take my word for it though. Hire a good lawyer and describe to them exactly what you wish to accomplish here. Perfect anonymity is probably very difficult but someone will have to make a minimal effort to track you on the play store.
Or better, consider making your app free and open source and make available on F-Droid. (: (I can try to convince you, can't I?)
