If you can't explain your app in fewer than 5 words, do you think your users will ever bother telling anyone about the app? Before you have product-market fit, product development is not about "adding features"—but distilling a product to a simple marketable sentence. Adding features more often impairs growth.

Nikita Biertwitter.com
David Sacksx.com

Eric Ries The Lean Startup: The Million Copy Bestseller Driving Entrepreneurs to Success