iOS開發icon圖標及載入圖各種尺寸

比例

2x = @2x 
Retina 4 = 568h@2x 
Retina HD 4.7 = @2x 
Retina HD 5.5 = @3x

iOS圖標

iPhone 6 Plus              @3x   180 x 180   
iPhone 6 && 5             @2x   120 x 120   
iPhone 4s                    @2x  120 x 120    
iPad && mini2+           @2x   152 x 152   
iPad 2 and iPad mini    @1x   76 x 76

iOS載入圖

iOS 7,8 (portrait )  2x              = 640 x 960   
iOS 7,8 (portrait )  Retina 4     = 640 x 1136   
Retina HD 4.7 (portrait)          = 750 x 1334   
Retina HD 5.5 (portrait)          = 1242 x 2208
Retina HD 5.5 (landscape)       = 2208 x 1242

參考：Apple – iOS Human Interface Guidelines

http://wenku.baidu.com/link?url=x0XeBvKabHUmZGabZusc6SEXXoEnKwWFKlIw4YqogCzVNw20uC3vFteaM_od4_3o3uG0OMSqP629Vq1SQMcJt5z0_iBeCotlgvX03-0lzEO

http://www.tuicool.com/articles/yEFbE3