Anyone sold pre-orders for native Mac or Win app before it's released? Does it works?

If you can't pre-sell it, you won't be able to sell it. If you're worried about not delivering - offer a discount for pre-purchases in order to lower the expectations.

Thanks for the advice! I'll start pre-selling soon. Now I'm working on a demo video, to show what's already done #zindex. Does anyone have experience selling software with Gumroad? Are they ok?