Before you do any development, I think you need to become your own product manager, which is essentially what an early-stage CEO does. Take the true lean approach and do some basic validation, wireframes, etc before commencing with any UX, UI or development. This will save time, money and greatly increase your odds of success.
Try these quick steps:
2. Based on that,create your own "click through" prototype that addresses your hypothetical user and value proposition and show it to potential users.Good prototyping tool
http://keynotopia.com- uses Keynote or Powerpoint to build a visual prototype that looks darn close to areal product.
3. Get your user validation and feedback, and make changes to the "prototype" until you're pretty sure you have the right product
4. THEN engage developers to build a real prototype, which can now be guided by the specific, iterated click-through prototype you just built; that provides clearer specs to a technical team as to what to implement.
Here's an in-depth talk I gave about product management in startups, with more about the above process and some more helpful tools and resources. The goal of the talk was to provide entrepreneurs with ideas - even non-coders - a good way forward to build and launch a product.