Trakt for iOS
Works on iPhone and iPad.
The second half of the show kinda drags a bit - the way Korean shows add scenes that don't add much to the story, and you can tell the scriptwriter changed things to accommodate the TV ratings - but the first half of the story, and some of the side story lines (e.g. Lee Jaekyung conspiracy, and the detectives) make the show worth finishing to the end.
