changing the height of UITabBar in iOS7/8?

For Swift 3 and xcode 8

extension UITabBar {
     override open func sizeThatFits(_ size: CGSize) -> CGSize {
     var sizeThatFits = super.sizeThatFits(size)
     sizeThatFits.height = 80 // adjust your size here
     return sizeThatFits
    }
 }

SomeGuy's answer above worked for me. Here's the Swift translation for anyone who may need it. I made the height close to what it seems most popular apps use.

class TabBar: UITabBar {

     override func sizeThatFits(size: CGSize) -> CGSize {
         var sizeThatFits = super.sizeThatFits(size)
         sizeThatFits.height = 38

         return sizeThatFits
     }
}

It seems everybody says this can't be done easily

In your storyboard give your UITabBar a custom subclass name, then implement the subclass with the following

This tells all views that use the tab bar that it should be a certain height.

@implementation MyTabBar

-(CGSize)sizeThatFits:(CGSize)size
{
    CGSize sizeThatFits = [super sizeThatFits:size];
    sizeThatFits.height = 100;

    return sizeThatFits;
}

@end