Yahoo!知恵袋 悩み相談できるQ&Aアプリ is a lifestyle app by Yahoo! JAPAN (LY Corporation) with 1,000,000+ downloads (about 4.6M estimated). +682 installs in the last 7 days. Rated 4.4 from 40K ratings. Released Aug 7, 2012. Install growth, rank history, SDKs and ad networks.
From the store listing: “A little doubt and troubles that can not be solved by one person are solved with the power of everyone!”