I hope you get offers to work on the backend with you. If not, here are some ideas:
(1) Find a like-minded person at meetup groups. The Atlanta Ruby User Group, for example, has a contingent actively working on public good kind of apps, things more for non-profit work than for-profit work. While your local technical meetup group is a good place to start, there is nothing stopping you from emailing the ATLRUG mailing list and asking. There are other platform meetups you can try, like ones for Node.js, Erlang/Elixir, various Python groups, etc.
(2) Use the Tim Ferris method of calling up famous people. You never know. Being someone versed in JS, you could try Resig, or Katz, or the AngularJS core folks. You could also try one of the startup CEOs/CTOs you admire. I don't think someone's work should be judged on the novelty of being young, but it happens (people think, could I have pulled it off at your age?) Older folks who have amassed experience and power like teaching and mentoring young people, as it is not as threatening to one's power base as young competition. You might not necessarily get such a person to work directly with you on the code, but you're likely to get access to a network that you normally would not have access to.
(3) Scour the web for other similar competitions and contact the winners. Maybe you can trade.
Good luck!