I found this site recently --> Korean grammar and spelling checker (run by 부산대학교!)
You type or paste in your text, click the "검사하기" button, and then it corrects your errors for you! (Followed by bewildering and sometimes overly long explanations.)
If there are no errors it'll say "문법 및 철자 오류가 발견되지 않았습니다."
Some words that I looked up:
검사 check, inspect
철자 spelling (also)
지적 point out, indicate
Korean spelling can be so tricky. And spacing. (Spacing gives me fits.) I hope this will be useful!