Pretty good, best so far [<- until Mac OS Mavericks, now broken]

Used to be a pretty good product. Contents seem to be the (*great*) New Ace for iOS. However won’t launch under 10.9. The Support link above is broken, too.

Anyway, the Ace dictionary is available in Mac OS’ Dictionary App, so maybe this app isn’t needed anymore.

Stephzfr about English Korean Dictionary, v2.0.1