The problem is that I don't even know if the idea is good so I'd like some feedback before actually coding it. Currently, it's just a very rudimentary prototype. The first thing that came to mind was product hunt. But now that I've actually looked at it, it seems to be more suited for products past the prototype stage (beta and beyond).
Product hunt know has "Upcoming" pages, is that the place to go?
Or here? Looking at the hastag "product-feedback-request" there doesn't seem to be that much feedback :-)