I am not convinced that if this went to court you WOULDNT get 50% at a minimum. A key buzzword in law is "reasonable". You guys had no contract in placed and ne

I am not convinced that if this went to court you WOULDNT get 50% at a minimum. A key buzzword in law is "reasonable". You guys had no contract in placed and never set or agreed to tentative terms. In the absense of that, I believe it is assumed that it is an equal partnership. The fact that it's a technology product and you did the lion's share of the work goes to your favor. At the end of the day you dont want to work with this guy anyway. If you're bent on being reasonable, I would tell him that the terms are 50-50 and nothing less. If he wants to get a lawyer he can. Remember that he is in the same place you are in. He cant just go start another company because you have the same claim on the IP that he does. So in order for him to do it completely detached from you, I would think he needs your sign off, which you wont give unless he expressly terminates your agreement. Hope this makes sense.