TwentyOne: Blackjack Trainer

Learn perfect basic strategy

Free · In‑App Purchases · Designed for iPad. Not verified for macOS.

TwentyOne is a clean, focused blackjack basic-strategy trainer. Learn the mathematically correct play for every hand, then drill it until it's second nature — in a calm, minimalist interface with no ads and no clutter. WHY TWENTYONE Basic strategy is the proven, optimal way to play every blackjack hand. TwentyOne doesn't just show you a chart — it computes the correct play for your exact table rules and helps you commit it to memory through fast, focused practice. THE STRATEGY CHART • The complete chart for hard totals, soft hands, and pairs • Color-coded for Hit, Stand, Double, Split, and Surrender • Tap any cell to see the expected value behind every option • Recomputes instantly when you change the rules PRACTICE THAT STICKS • Deal a hand, choose your action, and see the correct play right away • Modes: Random, Hard Totals, Soft Hands, Pairs, and Most Missed • "Most Missed" automatically resurfaces the hands you get wrong • Track your accuracy, streak, and performance by hand type PLAYS BY YOUR RULES Real tables differ, and so does correct strategy. Configure: • Number of decks (2, 4, 6, or 8) • Dealer hits or stands on soft 17 (H17 / S17) • Double after split, double rules, and late surrender • Resplit aces, hit split aces, and more The chart and every practice answer adjust automatically. TWENTYONE PRO Take your training further with a single one-time purchase — no subscriptions, no ads: • Expected value on every hand — see the full EV breakdown behind your decision after each practice hand, not just in the chart • Card Counting Trainer — master the Hi-Lo system with four focused drills: – Card Values: flash through the +1 / 0 / −1 tags until they're instant – Running Count: keep an accurate count as cards are dealt – Deck Countdown: race through a full deck down to zero – True Count: convert running count to true count on the fly Everything else in TwentyOne is free. MADE TO LOOK GOOD • Minimalist design with crisp, simple cards • Full light and dark mode • Three app icons to choose from • No ads, no accounts, no tracking — works offline for all training TwentyOne is for study and entertainment. It teaches optimal decision-making and involves no real-money play and no wagering.

Ratings & Reviews

  • 5.0
    out of 5
    2 Ratings

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.

Version 1.2.1

The developer, Justin Taddeo, 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 Not Collected

    The developer does not collect any data from this app.

    Privacy practices may vary, for example, based on the features you use or your age. Learn More

    Accessibility

    The developer has not yet indicated which accessibility features this app supports. Learn More

    Information

    Seller
    • Justin Taddeo
    Size
    • 2.2 MB
    Category
    • Casino
    Compatibility
    Requires iOS 17.0 or later.
    • iPhone
      Requires iOS 17.0 or later.
    • iPad
      Requires iPadOS 17.0 or later.
    • Mac
      Requires macOS 14.0 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 1.0 or later.
    Languages
    • English
    Age Rating
    18+
    In-App Purchases
    Yes
    Copyright
    • © 2026 Justin
  • Privacy Policy

    • More by Justin Taddeo

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