UIButton fails to properly register touch in bottom region of iPhone screen

Question

I have an app with many different buttons arranged in a calculator like, square / rectangular format. It is actually extremely similar to the default iOS calculator. There a

Answer 1

I've written a full solution in swift based on Luka's answer. Just make any conflicting buttons conform to this class and the problem will be gone:

class BorderBugFixButton : UIButton {

    override func awakeFromNib() {
        super.awakeFromNib()
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "unHighlight", name: UIApplicationWillResignActiveNotification, object: nil)
    }

    deinit {
        NSNotificationCenter.defaultCenter().removeObserver(self)
    }

    override func pointInside(point: CGPoint, withEvent event: UIEvent?) -> Bool {
        let inside = super.pointInside(point, withEvent: event)
        if inside != highlighted && event?.type == .Touches {
            highlighted = inside
        }
        return inside
    }

    internal func unHighlight() {
        highlighted = false
    }

}

P.S.: For those of you that don't like Storyboards/Xib's, just migrate the implementation of awakeFromNib() to init()