https://qooah.com/2015/06/04/%e3%80%8a%e7%89%a7%e5%a0%b4%e7%89%a9%e8%aa%9e%e3%80%8b%e5%b0%87%e6%8e%a8%e5%87%ba-ios-%e5%8f%8a-android-%e7%89%88-%e6%ad%a3%e5%82%b3%e9%81%8a%e6%88%b2/