https://purengom.com/2010/07/25/iphone%ec%9a%a9-pocket-informant-%ec%98%a4%ec%a0%84%ec%98%a4%ed%9b%84-%ed%91%9c%ec%8b%9c-%ed%95%b4%ea%b2%b0%eb%b0%a9%eb%b2%95/