Crayon Pop was in Jeju on the 22 Aug 2014 for the 11th Anniversary Arirang Radio Kpop Concert. They were there together with Park Myung Soo, Skull, Transfixion, K-much and Wings.
Selected pictures of Crayon Pop at the airport to Jeju are included with the full pack on their respective sites.
12 Oct 2014 Update: The official broadcast has aired.
Source: WondersOfJeju Facebook, Daum Fancafe, Tistory, Flickr