Tell me about your startup Idea, I will tell you if it's worth a $1bn?

Keeping in mind, people often need validation for their business ideas often Founders & Engineers miss the part whether their idea is worthy enough to pursue. So, I wanted Hacker news community to pitch their ideas in this forums as an experiment to see how many are comfortable sharing their ideas and also want them to get validated.

Please do expect fair amount of criticism about your ideas from others and me.