Do a limited (closed) beta, and test your hypothesis, which at this point currently goes something like: "This will be useful for other programmers and they wou

Do a limited (closed) beta, and test your hypothesis, which at this point currently goes something like: "This will be useful for other programmers and they would pay for it." So get some other programmers, privately, ask them to use it. See if they will. If nobody uses it, not even free, it's not useful. Once you have 5 people using it, invite more people and ask them to pay 10$/month. If nobody wants to pay for it, look harder, invite more people. If you do find some people, NOW you've got something. Now finish and polish the product and release.