Exactly what NURB said. It is offensive to a professional to ask for services for “maybe payment” once you become rich off of your idea. Not to be rude/negative, but a very small amount of ideas turn into millions. Right now it sounds like “co-founder” is just a nice way of saying “free labor”.
I’ve never gone to a doctor to ask for a free up front physical examination in promise that I will probably win a bicycle race with a huge prize at the end because of that doctor’s efforts.
The world doesn’t (and shouldn’t) work like that.