AppIcon size for iPhone:
29 - Settings @1x 29*29, 58 - Settings @2x 58*58, 87 - Settings @3x 87*87
40 - Spotlight @1x 40*40, 80 - Spotlight @2x 80*80
120 - iPhone @2x 120*120, 180 - iPhone @3x 180*180
for ipad:
76 - iPad @1x 76*76, 152 - iPad @2x 152*152
LaunchImage size for iphone:
Splash 640*1136
for ipad:
LaunchImage-Landscape~ipad 1024?×?768
LaunchImage-Landscape~ipad@2x 2048?×?1536
LaunchImage-Portrait~ipad 768?×?1024
LaunchImage-Portrait~ipad@2x 1536?×?2048
原文：http://www.cnblogs.com/ouyangfang/p/4952414.html