Instead of click a button to show facts...how can you implement a way t show it automatically?

Timer Feature

You'll want to look at the NSTimer Class Rreference for anything dealing with timers.

The method you'll want to read up on is +scheduledTimerWithTimeInterval:target:selector:userInfo:repeats: and to implement it in this app you can add one line to your viewDidLoad() method in the ViewController.swift file:

NSTimer.scheduleTimerWithTimeInterval(3.0, target: self, selector: Selector("showFunFact"), userInfo: nil, repeats: true)

I've used 3.0 as the interval, meaning it switches out every 3 seconds.

Shake Feature

To implement the shake to load fact feature you will again add a few things to the ViewController.swift file.

First, make the view able to become the first responder by adding:

override func canBecomeFirstResponder() -> Bool {
  return true
}

Then, make it the first responder by adding this line to the viewDidLoad() method:

self.becomeFirstResponder()

Last, implement the code to handle the shake gesture by overriding motionEnded:withEvent: method:

override func motionEnded(motion: UIEventSubtype, withEvent event: UIEvent) {
  if(event.subtype == UIEventSubtype.MotionShake) {
    showFunFact()
  }
}