Basta importar e usar minha categoria UIImageView simples.
#import "UIImageView+Rotate.h"
// repeatCount 0 for infinity loop
[_myImageView rotate360WithDuration:13 repeatCount:0];
gist: https://gist.github.com/alexhajdu/5658543
Download direto : https://gist.github.com/alexhajdu/5658543/download