Extension of UIButton to control its touch area.

Use CocoaPods.

pod 'UIButton+HitExtension'

Create UIButton, then set hitEdgeInsets.

UIButton *button = [[UIButton alloc] init];
button.hitEdgeInsets = UIEdgeInsetsMake(100.0f, 30.0f, 100.0f, 30.0f);

Congratulations! You're done.

UIButton+HitExtension is under WTFPL. You can do what the fuck you want with this shit. See LICENSE file for more info.