https://www.amazon.com/Lean-Customer-Development-Building-Cu...
Even if you have a revolutionary idea, and even if you can build it, it's still a waste of time if nobody will buy it. No matter how revolutionary your idea, you can try marketing it. If you are eventually going to sell it via a website, just build that website. If you're eventually going to sell it in person, just sell it in person. If you need a video demo, just make the demo. Then see what people do.
There are two reasons for this. The obvious reason is that you can save years of your life building something that nobody will pay for. But the subtle reason is that finding out what people actually want will usefully inform what you build. You can spend those years building the revolutionary product that people will buy, rather than the not-on-target product that they won't.
The techniques for this are not hard, and the Lean Startup literature has plenty to get people started. E.g., the Alvarez book on Lean Customer Development: https://www.amazon.com/Lean-Customer-Development-Building-Cu...
(And this is not to say that people shouldn't obsessively build things that interest them. I like doing that. It's a great way to learn and explore. But they shouldn't pretend that's a good way to start a business, any more than amateur musical noodling in one's basement is likely to produce the next #1 pop hit.)
When doing the UI/X later, this book helps a lot: http://www.amazon.de/Dont-Make-Think-Revisited-Usability-ebo...
I highly recommend this book.