---
title: "21 Sharp - Reviews, Revenue and Downloads in South Korea | Apple App Store"
description: "Turn the odds in your favor.  21 Sharp is a professional-grade blackjack trainer that teaches you basic strategy and card counting—the same techniques used by advantage players to beat the house.  BAS"
---

# 21 Sharp — South Korea

![21 Sharp App Icon](https://is1-ssl.mzstatic.com/image/thumb/Purple221/v4/33/4b/bb/334bbbcc-2651-70c1-7334-32e5200dfaa5/AppIcon-0-0-1x_U007epad-0-1-85-220.png/434x0w.png)

**Developer:** [busyslacker](https://apptail.io/developer/busyslacker-YzEc)
**Category:** Education
**Rating:** N/A (0 ratings)
**Price:** Free
**Bundle ID:** com.busyslacker.TwentyOneSharp
**Store:** Apple App Store
**Country:** South Korea
**Version:** 1.0 (released 2026-02-12)
**Original Release:** 2026-02-11
**Languages:** English

**App Store Link:** [Download on Apple App Store](https://apps.apple.com/kr/app/app/id6757319502)
**AppTail Page:** [https://apptail.io/app/21-sharp-fHzz/south-korea](https://apptail.io/app/21-sharp-fHzz/south-korea)

## 21 Sharp Description
Turn the odds in your favor.

21 Sharp is a professional-grade blackjack trainer that teaches you basic strategy and card counting—the same techniques used by advantage players to beat the house.

BASIC STRATEGY TRAINING
Learn the mathematically optimal play for every possible hand. Our quiz system drills you on 270+ hand combinations until perfect strategy becomes second nature. Reduce the house edge to just 0.5%.

CARD COUNTING DRILLS
Master the Hi-Lo counting system with speed-building exercises. Track running counts, calculate true counts, and learn when to increase your bets. Practice until you can count down a full shoe with accuracy.

PRACTICE TABLE
Play realistic blackjack hands with real-time strategy hints. See the running count, get recommendations for every decision, and learn from your mistakes without risking real money.

REFERENCE GUIDES
Access complete basic strategy charts and a comprehensive Hi-Lo counting guide anytime. Perfect for quick review before hitting the casino.

TRACK YOUR PROGRESS
Unlock 25+ achievements as you improve. Monitor your accuracy, streaks, and stats across all training modes. Watch yourself transform from beginner to sharp.

Whether you're preparing for Vegas, want to impress at home games, or just love the math behind the game, 21 Sharp gives you the edge.

Play Sharp. Win Sharp.

## 21 Sharp Screenshots
- [Screenshot 1](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/2f/d7/48/2fd7480f-ed32-1c40-8596-2c64a49f1d5c/iPhone_17_Pro_Max-01_HomeScreen.png/1320x2868.png)
- [Screenshot 2](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource221/v4/84/e3/e2/84e3e213-3343-5c08-a79c-4fd71461d30b/iPhone_17_Pro_Max-02_StrategyQuiz.png/1320x2868.png)
- [Screenshot 3](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/80/e2/f8/80e2f80b-4c25-79b1-9eab-19e71a6f3a56/iPhone_17_Pro_Max-03_CountingDrill.png/1320x2868.png)
- [Screenshot 4](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/e0/dd/d7/e0ddd735-0e76-2c8c-960e-cb032acb0c92/iPhone_17_Pro_Max-04_PracticeTable.png/1320x2868.png)
- [Screenshot 5](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/f3/9c/33/f39c337d-bf1c-d8ef-0afb-9721f59c390c/iPhone_17_Pro_Max-05_StrategyCharts.png/1320x2868.png)
- [Screenshot 6](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource221/v4/1b/a9/99/1ba99988-edcd-37b7-ea81-06dfec6ee035/iPhone_17_Pro_Max-06_Achievements.png/1320x2868.png)



## 21 Sharp In-App Purchases
| Item | Price |
|------|-------|
| 21 Sharp Premium | 4.40 ￦ |




## 21 Sharp Available In
- [South Korea](https://apptail.io/app/21-sharp-fHzz/south-korea)
- [Thailand](https://apptail.io/app/21-sharp-fHzz/thailand)

---

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