Best on the market
Easy training tool for beginners, or even good players. I use this on the plane to Vegas to get sharp. Great app.
Free
In-App Purchases
About
Master blackjack with a minimalist trainer that teaches mathematically correct plays for every hand. Practice with customizable rules and track your progress. Unlock advanced features like expected value and card counting with a one-time purchase.
✓Basic strategy chart for all hands
✓Customizable table rules
✓Practice modes for hands and pairs
✓Performance tracking
✓Expected value calculations
✓Card counting trainer (Hi-Lo system)
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What's New in TwentyOne
1.2.1
July 14, 2026
TwentyOne comes to iPad! The full trainer, redesigned for the big screen — a larger strategy chart that fits edge to edge, full-size practice cards, and tap-anywhere details in both portrait and landscape. Plus: strategy explanations now appear in the chart too — tap any hand to see why the play is right.
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In-App Purchases
$4.99
TwentyOne Pro
EV on every hand plus the Card Counting Trainer
User reviews
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FAQ
Does TwentyOne have ads?
No, TwentyOne is ad-free. The app is designed with a minimalist interface and no advertisements for an uninterrupted learning experience.
How much does TwentyOne cost?
The core blackjack basic strategy trainer is free. Advanced features, including the expected value breakdown and card counting trainer, are available with a one-time purchase called TwentyOne Pro.
Can I play TwentyOne offline?
Yes, all training features in TwentyOne work offline. The app does not require an internet connection for practice or strategy learning.
What blackjack rules can I customize in TwentyOne?
You can configure the number of decks (2, 4, 6, or 8), whether the dealer hits or stands on soft 17, double after split rules, late surrender, and more. The strategy chart and practice answers adjust automatically to your chosen rules.
What is the age rating for TwentyOne?
TwentyOne has an age rating of 17+. This is likely due to its association with casino games and gambling concepts.
How often is TwentyOne updated?
The latest version, 1.1.21, was released on June 26, 2026, indicating recent development activity. Updates typically focus on refining features and ensuring compatibility.
What are the card counting drills in TwentyOne Pro?
TwentyOne Pro includes four focused drills for the Hi-Lo card counting system: Card Values, Running Count, Deck Countdown, and True Count. These help users master the system for practical application.
What is the user sentiment for TwentyOne?
Based on the available data, user sentiment appears to be highly positive, with a rating of 5.0 stars from 1 rating. This suggests users find the app effective and well-designed.