Yes. The number one, guaranteed way to get a developer's attention is to go and sell your idea. Literally. Sell the would-be product to someone and get a contract. Sure, that contract will be full of outs for the buyer, but it's still a contract.

Getting to this point is a lot of work. It means you will have thought things through. It means you will have talked to your customers. It means you probably have mocked something up. You have probably invested a small amount of cash.

But mostly it means someone will pay for it which elevates your idea from "nope - waste of time unless you give me $20k" to "ok, we may have something here".

If you want to pay market rates (cash), I'd say show up with a mockup. If you want to convince a developer to join you for equity, show up with a sale.