https://qooah.com/2012/01/16/%e5%86%8d%e6%9c%89%e5%82%b3-android-market-%e7%9f%ad%e6%9c%9f%e5%85%a7%e4%b8%8d%e6%9c%83%e9%80%b2%e5%85%a5%e4%b8%ad%e5%9c%8b%e5%b8%82%e5%a0%b4/