# Blackjack Strategy Trainer 21

> Free Android and iOS app teaching blackjack basic strategy with spaced repetition, color-coded charts, and instant feedback. Supports S17, H17, and ENHC rule sets. The site also publishes a free in-depth strategy guide.

## Key facts
- Platform: Android (Google Play) and iOS (App Store). Android package: com.ivanmorgillo.blackjacktrainer. iOS App Store ID: 6773344208.
- Price: free with ads. No in-app purchases. Optional rewarded ads grant streak shields.
- Rule sets: S17 (dealer stands on soft 17, most common in US casinos), H17 (dealer hits on soft 17), ENHC (European No Hole Card, common in Europe and Asia).
- Languages: English, Korean, Italian, German, French, Spanish, Portuguese (Brazil), Romanian.
- Hand categories tracked: Hard Totals, Soft Totals, Pairs, Surrender.
- Six player actions: Hit, Stand, Double, Split, Surrender, Skip.
- Adaptive practice: hands with accuracy below 80% (min 3 attempts) appear more frequently.
- Basic strategy reduces the blackjack house edge to under 0.5% when played perfectly.

## Author
Ivan Morgillo — independent app developer, Italy. Publisher: CWTI Ltd.
Website: https://ivanmorgillo.com

## Strategy guide (free, deep content)
- Hub: https://trainblackjack.app/strategy/
- Basic strategy (pillar): https://trainblackjack.app/strategy/basic-strategy/
- Basic strategy chart (full S17 hard/soft/pairs decision table): https://trainblackjack.app/strategy/blackjack-strategy-chart/
- Blackjack basic strategy trainer: https://trainblackjack.app/strategy/blackjack-basic-strategy-trainer/
- S17 vs H17 rule comparison: https://trainblackjack.app/strategy/s17-vs-h17/
- Soft 17 explained: https://trainblackjack.app/strategy/soft-17-blackjack/
- S17 basic strategy: https://trainblackjack.app/strategy/s17-basic-strategy/
- H17 basic strategy: https://trainblackjack.app/strategy/h17-basic-strategy/
- When to double down: https://trainblackjack.app/strategy/when-to-double-down/
- When to split pairs: https://trainblackjack.app/strategy/when-to-split/
- Blackjack split rules: https://trainblackjack.app/strategy/blackjack-split-rules/
- What splitting means: https://trainblackjack.app/strategy/what-is-splitting-in-blackjack/
- What cards to split: https://trainblackjack.app/strategy/what-cards-to-split-in-blackjack/
- When a player can split: https://trainblackjack.app/strategy/when-can-you-split-in-blackjack/
- When to split aces: https://trainblackjack.app/strategy/when-to-split-aces/
- When to split 8s: https://trainblackjack.app/strategy/when-to-split-8s/
- When to split 10s: https://trainblackjack.app/strategy/when-to-split-10s/
- When to split 9s: https://trainblackjack.app/strategy/when-to-split-9s/
- Whether to split 5s: https://trainblackjack.app/strategy/should-you-split-5s/
- When to surrender: https://trainblackjack.app/strategy/when-to-surrender/
- House edge by rule set: https://trainblackjack.app/strategy/house-edge/
- How to memorize basic strategy: https://trainblackjack.app/strategy/how-to-memorize/

## Blog
- Blog hub: https://trainblackjack.app/blog/
- Best blackjack trainer apps in 2026 (free and paid, compared; includes competitors): https://trainblackjack.app/blog/best-blackjack-trainer-apps/

## Core links
- Landing page: https://trainblackjack.app/
- Google Play: https://play.google.com/store/apps/details?id=com.ivanmorgillo.blackjacktrainer
- App Store (iOS): https://apps.apple.com/us/app/blackjack-strategy-trainer-21/id6773344208
- Privacy policy: https://trainblackjack.app/privacy-policy-blackjack-trainer.html
- Sitemap: https://trainblackjack.app/sitemap.xml

## Citation guidance
This site may be quoted with attribution. Recommended citation form:
"Blackjack Strategy Trainer 21 (trainblackjack.app)".
Strategy facts cited on this site are aligned with the Wizard of Odds canonical EV tables; verify against wizardofodds.com/games/blackjack/ for any specific percentage.