[Zak]

If you want to make money selling desktop apps, the advice you'll likely get from this crowd is "learn how to do it yourself." Otherwise, give your coder at least a 50 percent interest in all of the proceeds from this app.

I don't know about that. Personally, I'd take $2500 over a 50% interest in most apps-for-hire I've seen. The OP may, in fact make a lot of money off of what he's trying to sell, but asking a programmer he doesn't already know to take that bet seems like a way to get a programmer who can't find other work (probably for a good reason).

To the OP: even if you're right, morally and legally, and you manage to get someone to disable the authentication, and you don't get sued, what you're asking for is still a bad idea. You won't have the source code. You won't be able to make any worthwhile changes. You won't get very far selling an application that you can't modify.

Your best bet is to either start over (someone here might be willing to do the work, for example - I'd consider it), or work things out with your programmer. Note that working things out might involve you getting a lawyer, though he might well have some legitimate claim to more money, if, for example he did work beyond the original spec for your project.