Is it possible to change the font size of tabs?
I recommend a better way:
[yourTabBarItem setTitleTextAttributes:[NSDictionary dictionaryWithObjectsAndKeys:
[UIColor whiteColor], UITextAttributeTextColor,
[NSValue valueWithUIOffset:UIOffsetMake(0,0)], UITextAttributeTextShadowOffset,
[UIFont fontWithName:@"Helvetica" size:18.0], UITextAttributeFont, nil]
forState:UIControlStateNormal];