self.navigationItem.title = @"my title"; //sets navigation bar title.
self.tabBarItem.title = @"my title"; //sets tab bar title.
self.title = @"my title"; //sets both of these.
参考:http://blog.csdn.net/huifeidexin_1/article/details/8078118
UITabBarItem title 和self.title设置不同的标题
原文：http://www.cnblogs.com/mapanguan/p/7000391.html