I saw something similar on here a few days ago and I would love to do this as well.
I have been doing ruby on rails for about 1.5+ years and I am looking to expand my portfolio with some projects and I currently have some time to do freelance work.
This could be your minimum viable product(MVP). This could be what you link to in incubator applications. Just a web application that closely matches your basic vision.
I would be able to do very basic design based on mockups you give me.(Mockups, sketches and any graphics and copy text you want me to include)
I am willing to work 1-2 weeks per project so that I can build out your basic idea/prototype.
Let me know if you have any questions/ideas or just message me @ hnprototype[at]gmail.com
Price range for projects $800 - $1500