Comparison

memoryOS vs Zetamac problems

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

memoryOS

Enhance your memory with interactive lessons and a 3D virtual mind palace game. This app uses scientifically proven techniques like spaced repetition to boost long-term memory storage and knowledge retention. It's designed to make memorization skills joyful and effective for everyone.

Highlights
  • Interactive memory lessons
  • 3D Virtual Mind Palaces
  • Spaced repetition system
  • Gamified learning
  • Memorize names, lists, numbers, and more
  • Advanced study techniques
Features
Read full description

memoryOS contains interactive bite-sized lessons by a 2X World Memory Champion and an educational 3D game of Virtual Mind Palaces - all in one easy-to-use app. It utilizes scientifically proven memory techniques, spaced repetition and patented game mechanics to enhance long-term memory storage and improve knowledge retention. memoryOS is loved by 500,000+ people worldwide because it is a whole new, joyful & game-changing tool for obtaining the most effective memorization skills. Co-founded by Jonas von Essen, who went from struggling to remember to becoming a World Memory Champion, winning on Who Wants To Be a Millionaire, "Jeopardy, and setting a world record by memorizing 100,000 decimals of Pi . memoryOS app has over 18k public worldwide ratings on Apple and Google app stores combined, averaging 4.8 stars. Users also continue adding 5-star reviews daily, sharing how effective and life-changing memoryOS has been for them. Also, memoryOS remains the most crowdfunded app in Kickstarter’s history. Memorization is as important as reading and writing and should be taught as our base skill. Our mission is to enable millions of people to remember needed information easily. With memoryOS, you will learn how to memorize: - Names, Long speeches, Lists of items, Birthdays, Personal facts, Passwords, Trivia, Languages, Vocabulary and phrases, Countries and Capitals, Flags, Historical timeline, Numbers, Periodic table - Content of complete books, Dates of significant events, Complex data structures, Concepts, and figures - Art, Anatomy, Decks of cards, Advanced number systems; Long sequences of numbers, Binary Digits You will also learn: - How to keep track of years, months, weeks, and days - Advanced study techniques, Spaced Repetition system, Speed memorization Why did Google Brands Accelerator recognize memoryOS as being 'Light Years Ahead' in the memory space? • memoryOS delivers results: During our pre-launch phase, thousands of users completed our demo and, on average, had a 70% increase in recall and a 60% increase in recall speed just after the first ~40min session. • Providing your mind with structured storage space: We have spent tens of thousands of hours creating and optimizing our Virtual Mind Palaces, so you don’t have to spend months constructing your own the hard way. These virtual palaces serve as blueprints for your mind's storage space, allowing you to easily encode, store and recall like a memory champion. • A proven innovative approach that works: During our research and development stage, thousands of people of all age groups and even those with difficult medical conditions found memoryOS as an effective and useful tool. Actual results exceeded our team’s expectations. • Gamified edtech at its best: memoryOS has proven to work on people with no prior gaming experience - anyone can use it. Utilizing the power of the Unity game engine, memoryOS is widely accessible on all mobile and tablet devices and is soon coming to VR. -- Joining memoryOS is free. This provides extensive value on the free plan, and you are not obligated to pay to start using it. You can subscribe to a Student Premium plan for as low as $3.49/month when billed annually or $4.99/month when billed monthly (it can be 10-20% higher in some countries due to local taxes). You can subscribe through the 'Shop' section of the memoryOS app and find the above-mentioned or go to your App Store app's profile and choose a desired plan there. Recurring payments will automatically renew unless you cancel your account at least 24 hours before the end of the current subscription period. You can manage your subscription, cancel anytime, or turn off auto-renewal by accessing your iTunes account. Join the memoryOS community of over 500,000+ early adopters who share this memorable journey! -- Terms: memoryOS.com/terms Privacy policy: memoryOS.com/privacy-policy Learn more at: memoryOS.com Contact us: support@memoryOS.com

About

Zetamac problems

Sharpen your math skills with daily practice covering various problem types. Customize difficulty, practice under timed conditions, and receive instant feedback to prepare for exams and interviews.

Highlights
  • Diverse math problem types
  • Customizable number range
  • Timed practice mode
  • Realistic quantitative problem simulations
  • Instant feedback
Features
Read full description

Zetamac is the ultimate math practice tool designed to help you sharpen your mathematical skills and prepare for competitive exams, interviews, and personal growth. Whether you're preparing for quant interviews, standardized tests, or simply looking to enhance your mental math abilities, Zetamac offers a fun and engaging way to practice a wide variety of math problems. With its user-friendly interface and customizable settings, this app is perfect for users of all ages and skill levels. Key Features: Diverse Math Problem Types: Zetamac includes multiple problem types such as addition, subtraction, multiplication, and division, offering a well-rounded mathematical experience. Each problem type is carefully designed to help you master different aspects of math and improve your problem-solving abilities. Customizable Number Range: Customize the difficulty level of the problems by adjusting the number range. Whether you’re looking for simple arithmetic or complex calculations, you can tailor the app to your skill level. This makes Zetamac ideal for anyone from beginners to advanced users. Timed Practice: Compete against the clock and improve your speed and accuracy. Zetamac’s countdown timer allows you to practice under pressure, mimicking the time-sensitive nature of real-life math challenges like those encountered in quant interviews. Realistic Quantitative Problem Simulations: Zetamac's math problems closely resemble the types of questions you might encounter in quant interviews, where the ability to quickly and accurately perform calculations is essential. The app's division problems, for example, simulate reverse multiplication, teaching you how to quickly identify relationships between numbers—a crucial skill for many finance and consulting roles. Instant Feedback: After answering each problem, Zetamac provides instant feedback to let you know whether your answer is correct or incorrect. This immediate reinforcement allows you to learn from your mistakes and ensures you're continually improving your skills.

Screenshots

memoryOS4 screens
Zetamac problems3 screens

Verdict

The call

The clearest difference is in-app purchases: Zetamac problems at none against memoryOS's 10. memoryOS's advantage is ads (none vs shown) and ratings volume (17K vs 2). On price, rating, device support and iOS requirement there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. memoryOS sells 9 in-app purchases, starting at $5.99 per month. Zetamac problems asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.9 for memoryOS against 5.0 for Zetamac problems. That said, the two scores are not equally well evidenced: memoryOS has 17K ratings behind it against 2, so its average is the more settled of the two.

UpkeepUpdate frequency

memoryOS ships an update fortnightly, Zetamac problems every 2 months. The most recent releases landed on November 10, 2026 and November 8, 2026 respectively.

Scorecard6 real differences · 5 level
memoryOS versus Zetamac problems: the parameters behind the verdict, then further details
ParametermemoryOSZetamac problems
PriceFreeFree
Rating4.9 (17K ratings)5.0 (2 ratings) — better
Positive reviews80.2% of reviews—
Number of ratings17K — better2
Update frequencyFortnightly — betterEvery 2 months
AdsNo — betterYes
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesAd-supported — better
Best chart rank#56 — better—
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.2 — better16.0
Further details — not scored
Size232 MB4 MB
Age rating4+4+
DeveloperEncoder Inc.Chhaya Patel

Customer experience

memoryOS

All ratings17,203 ratings
Positive97.2%
Neutral1.0%
Negative1.8%
Written reviews1,723 reviews
Positive80.2%
Neutral5.0%
Negative14.9%

Zetamac problems

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Bugs and requests

memoryOS

Reported bugs

5 issues
  • 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

5 requests
  • 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

Zetamac problems

Not enough reviews yet to summarise bugs or requests.

In-app purchases

9 purchases

memoryOS

Subscriptions9
  • Student Monthly Plan7 Days trial$5.991 Month
  • Essential Weekly Plan7 Days trial$6.997 Days
  • Essential Monthly Plan$15.991 Month
Show 6 more
  • Expert Monthly Plan$27.991 Month
  • Essential Annual Plan7 Days trial2 variants$89.991 Year
  • Expert Annual Plan7 Days trial$148.991 Year
  • Expert Annual Plan1 Month trial$149.991 Year
  • Expert Annual Plan7 Days trial$159.991 Year
  • Expert Annual Plan1 Month trial$159.991 Year
None

Zetamac problems

No in-app purchases

Questions

Is memoryOS free?
memoryOS is free to download, with in-app purchases available.
Is Zetamac problems free?
Zetamac problems is free to download, with no in-app purchases.
Which has better reviews, memoryOS or Zetamac problems?
Zetamac problems is rated higher. memoryOS averages 4.9 out of 5 from 17K ratings, while Zetamac problems averages 5.0 from 2 ratings.
Do memoryOS or Zetamac problems have ads?
Zetamac problems shows ads; memoryOS does not.
Which is updated more often, memoryOS or Zetamac problems?
memoryOS ships an update fortnightly, and Zetamac problems every 2 months. Most recently, memoryOS was updated on November 10, 2026 and Zetamac problems on November 8, 2026.

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