Do not under any circumstances sign anything. Copyright (http://www.copyright.gov/register/index.html http://www.copyright.gov/register/index.html) your code im

Do not under any circumstances sign anything. Copyright (http://www.copyright.gov/register/index.html http://www.copyright.gov/register/index.html) your code immediately. Then play hardball. Tell him you feel that you have done most of the work and want 60% or you will go your separate ways. If he is threatening legal action, take legal action first. File a complaint if he even touched your software. (Uploads it to a server, tries to give it to another developer to reverse engineer, etc.). Don't say anything in email or verbally that you may regret later. In fact, assume that when you talk to him, whatever either of you say may be used in court. Start going it alone right away. Try to market and sell the product by yourself. Your wrote it. Its yours. He might try to take you to court over this in that you had some "verbal" agreements wrt a joint venture and he probably has some emails to back him up (M. Arrington et. al.) so it is imperative that you either placate him or take legal action first.