Here is my solution to this problem with review and credibility built in.
Github exists for coders, people are massaging it for other projects. Crowdsourcing platforms are many but each have their faults.
I am building a platform for anyone to contribute to projects.
We are disrupting the future of work. PLease check out
www.crowdraising.co/metacampaign
and there is an explainer video that does the job
<a href="https://www.youtube.com/watch?v=w3QT4lqco8M" rel="nofollow">https://www.youtube.com/watch?v=w3QT4lqco8M</a>
You are already on the right path.
Communities like hackernews and product hunt are good for early adopters
Quora,FB groups and meetups are next.
Online SEO AdWords will get you some traffic.
Best would be have ambassadors/refferars
Communities in the real world that cater to your product or service are better for RoI