A custom PinAnnotationView. The project, "ResizableMKCircleOverlay", is so good, but still has insufficiency for me. It only work on one object. My case is needed to add pin(one or more) at any time. So, I modify some code and make this project. There are a image pin view & resize circle overlay.
Have a custom image pin-annotation view. Dynamic multi-resizable MKCircle Overlay