title: Having Placemark/Annotation in the center of your mapView, even if you scroll
body: <p>I've spent many hours trying to figure how to do this:</p>
  
  <p><img src="https://i.stack.imgur.com/KUoFG.png" alt="enter image description here"></p>
  
  <p>Having a placemark/annotation in the centerCoordinate of your mapView, when you scroll the map, the placemark should always stays in the center.</p>
  
  <p>I've seen another app doing this too!</p>