What dmix said. Why are you using a throwaway account?

A co-founder relationship is very important, and my willingness to join you on this venture has less to do with your idea and more to do with you. Specifically:

- Who are you, and what have you done?

- What is your professional and personal experience, and what does it bring to the table in a general sense of running a startup, and in a specific sense, this idea of yours.

- Why you? I need to be able to trust my co-founder pretty much absolutely and unquestionably. What is your character and who can vouch for it?

Funnily enough, your idea and the fact that you have a prototype is a fairly minor signal compared to the above.