Check out Word Circle (동그라미) - a Korean vocabulary game. It's available on Android and iOS.
Android update including pronunciations, search in English and verb definitions
Pronunciation breakdowns are now available. If you are learning Korean type in any word and see a breakdown of how each consonant and vowel is pronounced. Examples: 국물 or 소리
"Choi" appears to be a Romanized Korean name.
[🔊 click to pronounce]