First of all, thanks so much for your comment. You are right, my overviews are too brief coz I don't want to write a long essay here to scare off people or point you guys to my own blog. I want to start the discussion first.

1)HR You're right. Personal info is sensitive but for Basecamp, Mint, and Zendesk. They also manage customers' confidential information. I believe there should be some ways to solve this problem. What's your thought?

2)Decision Tree I am sorry that this one is a little bit confusing. The app will actually let you input your utility of each choices and calculate the best choice for you. I think Hunch is guessing your best choice. But my app will be like a calculator. You have to input other choice and path yourself. You can check out the more detailed idea on HBR:

http://harvardbusiness.org/product/decision-trees-for-decisi...

3)Math Good question. Monetizing this could be difficult. I think I will just focus on the US in the beginning. Do you think monetizing it by related services like real-time tutoring, and premium questions and games are possible? I just think if parents are willing to pay for Club Penguin, they should be willing to pay for education as well. Would love to hear your comments.

Million Thanks!