# Learn Cryptography vs 21 Sharp

The clearest difference is ads: 21 Sharp at none against Learn Cryptography's shown. Learn Cryptography's advantage is iOS requirement (15.1 vs 17.0). On price, rating, ratings volume and in-app purchases there is nothing between them.

Both are free to download. Learn Cryptography sells 4 in-app purchases, starting at $3.99 per 7 days and 21 Sharp sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

On the App Store both sit at effectively the same score — 5.0 for Learn Cryptography against 5.0 for 21 Sharp. Both are backed by a comparable volume of ratings — 1 and 1 respectively.

## The numbers

| Metric | Learn Cryptography | 21 Sharp |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (1 ratings)](https://appshunter.io/ios/app/learn-cryptography-encryption/id6742056134/reviews) | [5.0 (1 ratings)](https://appshunter.io/ios/app/21-sharp/id6757319502/reviews) |
| Number of ratings | 1 | 1 |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | Every 3 weeks | — |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 67 MB | 1 MB |
| Requires iOS | **15.1** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 12+ |
| Developer | [MEHMET CANKER (TR)](https://appshunter.io/developer/1565350155) | [busyslacker llc](https://appshunter.io/developer/1576079901) |

## What reviewers say

### Learn Cryptography

[App page](https://appshunter.io/ios/app/learn-cryptography-encryption/id6742056134)

Master the art and science of cryptology with an AI-powered learning app. Explore encryption, decryption, ciphers, and cryptographic systems through interactive tools, puzzles, and a structured curriculum. Ideal for beginners to professionals seeking to understand digital security.

**Highlights:** AI-powered tutor for step-by-step explanations, Interactive encryption and decryption tools, Cryptography playground for practical exercises, Gamified puzzles and challenges, Structured curriculum from beginner to advanced, 24/7 AI chat support for clarifications

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly Subscription | $3.99 | per 7 days |
| Monthly Subscription | $4.99 | per month |
| Yearly Subscription | $8.90 | per year |
| Lifetime Subscription | $19.90 | one-time |


### 21 Sharp

[App page](https://appshunter.io/ios/app/21-sharp/id6757319502)

Master blackjack strategy and card counting with this professional-grade trainer. Learn optimal plays, practice counting systems, and track your progress with realistic simulations and reference guides. Reduce the house edge and gain a competitive advantage.

**Highlights:** Basic strategy training, Card counting drills (Hi-Lo), Realistic practice table, Reference guides, Progress tracking and achievements

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 21 Sharp Premium | $2.99 | one-time |


## Frequently asked questions

### Is Learn Cryptography free?

Learn Cryptography is free to download, with in-app purchases available.

### Is 21 Sharp free?

21 Sharp is free to download, with in-app purchases available.

### Which has better reviews, Learn Cryptography or 21 Sharp?

Learn Cryptography and 21 Sharp are both rated 5.0 out of 5 on the App Store, from 1 and 1 ratings respectively.

### Do Learn Cryptography or 21 Sharp have ads?

Learn Cryptography shows ads; 21 Sharp does not.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*