Blackjack Trainer: TwentyOne
Basic Strategy & Card Counting
Only for iPhone
Free · In‑App Purchases
iPhone
Stop guessing at the blackjack table. TwentyOne helps you learn basic strategy, practice real decisions, and build Hi-Lo card counting skills with instant feedback.
LEARN BLACKJACK STEP BY STEP
Build a strong foundation with a structured curriculum that takes you from the rules of the game to hard hands, soft hands, pair splitting, advanced concepts, casino readiness, and card counting.Lessons are designed to be practical and easy to apply at the table — not just information to memorize.
PRACTICE REAL DECISIONS
Train with realistic blackjack hands and make the same decisions you'll face in live play: Hit, Stand, Double, Split, or Surrender.
Get immediate feedback after each decision, see the better play when you miss, and understand why it was correct.
Practice adapts to your mistakes so you can spend more time on the hands that need work.
MASTER BASIC STRATEGY
Use the interactive strategy chart to study hard totals, soft totals, and pairs.
Customize common table rules, including:
• Dealer Hits or Stands on Soft 17
• Double After Split
• Late Surrender
Your strategy chart and practice sessions adjust to match your selected rules.
BUILD HI-LO CARD COUNTING SKILLS
Learn card counting progressively with focused drills:
• Flash Drill — memorize Hi-Lo card values
• Pair Practice — recognize cancellation quickly
• Running Count — maintain an accurate count through card sequences
• True Count — convert the running count using decks remaining
• Ramp Mode — increase speed and difficulty as you improve
TRACK YOUR PROGRESS
See your accuracy, hands played, sessions, streaks, recent performance, and results by category.
TwentyOne highlights areas that need more work so you always know what to practice next.
BUILT FOR PRACTICE
• Structured blackjack lessons
• Adaptive decision training
• Instant explanations
• Configurable strategy charts
• Hi-Lo counting drills
• Detailed performance statistics
Whether you're learning blackjack from scratch or sharpening skills you already have, TwentyOne gives you one place to learn, drill, review, and improve.
Download TwentyOne and start making every decision with more confidence.
TwentyOne is an educational training tool. It does not involve real-money gambling and does not guarantee winnings or profit. Blackjack outcomes involve chance.
Ratings & Reviews
We’ve made several improvements to make the app faster, smoother, and more reliable.
The developer, Ryan Herga, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Used to Track You
The following data may be used to track you across apps and websites owned by other companies:
- Usage Data
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Usage Data
- Diagnostics
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Ryan Herga
- Size
- 66.2 MB
- Category
- Card
- Compatibility
Requires iOS 15.1 or later.
- iPhone
Requires iOS 15.1 or later. - iPod touch
Requires iOS 15.1 or later.
- iPhone
- Languages
- English
- Age Rating
13+
- 13+
- In-App Purchases
Yes
- Monthly Premium $3.99
- Annual Premium $19.99
- Lifetime Premium $39.99
- Copyright
- © 2026 Ryan Herga