There are only a few web apps I think can be useful within this 3 hour construct. I think it's much better to develop a web app that takes about a weekend or ma

There are only a few web apps I think can be useful within this 3 hour construct. I think it's much better to develop a web app that takes about a weekend or maybe 2 to complete. You get something with a lot more value and can truly extend your ideas outward. Furthermore, a weekend still provides the construct of "fast." Building a web app in 3 hours will leave you at best with something like threewords.me or its clones. While those can go viral, they rely heavily on luck. Why not spend 2 hours and build a beautiful and captivating launch page for an idea that would take you a weekend or two to build. Then, spend 1 hour reposting it everywhere and try to get feedback. This way, you can see if the concept itself gets any traction.