Changing font size of tabbaritem

Question

Is it possible to change the font size of tabs?

Answer 1

[Update] iOS 7.0+ version of @cancer86's nice answer:

[[UITabBarItem appearance] setTitleTextAttributes:[NSDictionary dictionaryWithObjectsAndKeys:
                                                   [UIColor whiteColor], NSForegroundColorAttributeName,
                                                   [UIFont fontWithName:@"Helvetica" size:tabFontSize],
                                                   NSFontAttributeName,
                                                   nil] forState:UIControlStateNormal];

[[UITabBarItem appearance] setTitleTextAttributes:[NSDictionary dictionaryWithObjectsAndKeys:
                                                   [UIColor redColor], NSForegroundColorAttributeName,
                                                   [UIFont fontWithName:@"Helvetica" size:tabFontSize], NSFontAttributeName,
                                                   nil] forState:UIControlStateSelected];

The main change is that UITextAttributeTextColor and UITextAttributeFont are both deprecated

In order to apply it to all tabs (thanks to @ToolmakerSteve for pointing out)

for(UIViewController *tab in  self.tabBarController.viewControllers)
{        
    [tab.tabBarItem setTitleTextAttributes: ...];
}