# memoryOS vs Blackjack Mastery 21 Trainer

The clearest difference is ads: memoryOS at none against Blackjack Mastery 21 Trainer's shown. memoryOS also leads on chart position (#66 vs unranked). On price, update cadence, in-app purchases and device support there is nothing between them.

Both are free to download. memoryOS sells 23 in-app purchases, starting at $3.99 per 7 days and Blackjack Mastery 21 Trainer sells 4 in-app purchases, starting at $9.99 per month. Whichever you choose, the download price is not the number that matters.

memoryOS ships an update every 2 weeks, Blackjack Mastery 21 Trainer every 3 weeks. The most recent releases landed on October 26, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | memoryOS | Blackjack Mastery 21 Trainer |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.9 (17K ratings)](https://appshunter.io/ios/app/memoryos-memory-games/id1553283646/reviews)** | — |
| Number of ratings | **17K** | — |
| Positive reviews | 80.3% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | **No** | Yes |
| Update frequency | **Every 2 weeks** | Every 3 weeks |
| Monetization | Free with in-app purchases | — |
| Best chart rank | **#66** | — |
| Size | 231 MB | 44 MB |
| Requires iOS | 15.2 | **15.1** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 17+ |
| Developer | [Encoder Inc.](https://appshunter.io/developer/1524669695) | [Anton Terekhov](https://appshunter.io/developer/1778000768) |

## What reviewers say

### memoryOS

[App page](https://appshunter.io/ios/app/memoryos-memory-games/id1553283646)

**Currently charting:** #66 Top Grossing · Education, #105 Top Free · Education (US App Store)

Enhance your memory and focus with interactive lessons and a virtual mind palace game. Learn scientifically proven techniques to improve knowledge retention and recall a wide range of information, from names and numbers to complex data and entire books.

**Highlights:** Interactive bite-sized lessons, Virtual Mind Palaces game, Spaced repetition system, Scientifically proven techniques, Improve knowledge retention, Memorize diverse information

**Features:** Vision Pro support

**In-app purchases (23)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Student Weekly Plan | $3.99 | per 7 days |
| Student Monthly Plan | $5.99 | per month |
| Expert Weekly Plan | $6.99 | per 7 days |
| Essential Weekly Plan | $6.99 | per 7 days |
| Essential Monthly Plan | $14.99 | per month |
| Essential Monthly Plan | $14.99 | per month |
| Essential Monthly Plan | $16.99 | per month |
| Student 3 Months Plan | $19.99 | per 3 months |
| Expert Monthly Plan | $24.99 | per month |
| Expert Monthly Plan | $29.99 | per month |
| Expert 3 Months Plan | $49.99 | per 3 months |
| Expert 3 Months Plan | $69.99 | per 3 months |
| Expert 6 Months Plan | $89.99 | per 6 months |
| Essential Annual Plan | $89.99 | per year |
| Essential Annual Plan | $89.99 | per year |
| Essential Annual Plan | $89.99 | per year |
| Expert Annual Plan | $148.99 | per year |
| Expert Annual Plan | $149.99 | per year |
| Expert Annual Plan | $174.99 | per year |
| Expert Annual Plan | $174.99 | per year |
| 10 Hearts | $0.99 | one-time |
| 10 Loci Coins | $2.99 | one-time |
| 50 Loci Coins | $14.99 | one-time |

**What reviewers like**

- 🚀 Effective memory techniques
- 👍 Interactive and engaging
- 💡 Innovative use of memory palaces
- 🤩 Impressive results in a short time
- 🎉 Fun and enjoyable to use

**What reviewers complain about**

- 💰 Expensive subscription model
- 🐛 Buggy and crashes frequently
- 🤔 Confusing navigation and UI
- 🔒 Lack of transparency around pricing
- 🙄 Aggressive upselling and marketing tactics

**Reported bugs**

- Login issues and account management problems
- Frequent crashes and app instability
- Navigation and UI elements not working as expected
- Syncing issues between devices and lost progress
- Connectivity problems when using cellular data

**Requested features**

- More free content and lessons
- Ability to create custom memory palaces
- Better progress tracking and analytics
- Integration with other learning/productivity apps
- Offline mode for lessons and memory palaces


### Blackjack Mastery 21 Trainer

[App page](https://appshunter.io/ios/app/blackjack-mastery-21-trainer/id6744902920)

**Features:** macOS Compatibility

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Access | $9.99 | per month |
| Premium Access | $39.99 | per year |
| Premium Access | $39.99 | per year |
| Premium Access | $99.99 | one-time |


## Frequently asked questions

### Is memoryOS free?

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

### Is Blackjack Mastery 21 Trainer free?

Blackjack Mastery 21 Trainer is free to download, with in-app purchases available.

### Do memoryOS or Blackjack Mastery 21 Trainer have ads?

Blackjack Mastery 21 Trainer shows ads; memoryOS does not.

### Which is updated more often, memoryOS or Blackjack Mastery 21 Trainer?

memoryOS ships an update every 2 weeks, and Blackjack Mastery 21 Trainer every 3 weeks. Most recently, memoryOS was updated on October 26, 2026 and Blackjack Mastery 21 Trainer on October 11, 2026.

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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.*