Doomsday calculator memory vs Aritmo
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Doomsday calculator memory
Practice and memorize a method for quickly calculating the weekday of any given date. This app is based on John Conway's 1970 mathematical system, allowing you to test your abilities without external tools.
- Practice date calculations
- Memorize weekday method
- Based on John Conway's system
- No external tools needed
- Test your abilities
Read full descriptionHide full description
In 1970, British mathematician John Conway devised a way to quickly calculate the weekday of any given date without the help of calculators, computers, or calendars. This app helps you to practice and memorize.
Aritmo
Read full descriptionHide full description
Train your brain to calculate faster with short, structured mental math lessons. Aritmo teaches rapid calculation techniques through focused lessons, interactive practice, and gamified challenges. Instead of memorizing random tricks, you learn step-by-step methods for solving arithmetic problems more efficiently in your head. LEARN MENTAL MATH STEP BY STEP Aritmo is designed to help you build real calculation skills through progressive courses and practice exercises. In this first version, Aritmo includes two main learning paths: • Basic Multiplication Learn the Trachtenberg method for rapid multiplication with numbers from 2 to 11. This course introduces the core patterns and rules used to multiply faster mentally. • General Multiplication Learn a broader multiplication method for solving more flexible multiplication problems. This course is available with an active subscription. The app clearly identifies which content is included and which content requires a subscription before purchase. PRACTICE WITH SHORT DAILY LESSONS Each concept is broken into simple lessons that can be completed in a few minutes. You can learn a method, practice it immediately, and repeat challenges to build speed and confidence over time. Aritmo helps you practice: • Fast multiplication techniques • Mental arithmetic without a calculator • Number patterns that simplify calculations • Focused repetition for stronger recall • Progressive exercises that increase in difficulty GAMIFIED BRAIN TRAINING Aritmo turns mental math practice into a structured daily challenge. You can: • Progress through lessons • Complete practice exercises • Build learning streaks • Track your progress • Improve your speed through repetition WHO IS ARITMO FOR? Aritmo is useful for: • Students who want stronger arithmetic skills • Adults who want to sharpen their mental calculation ability • Puzzle and brain-training enthusiasts • Anyone curious about rapid mental math methods • Learners who want structured practice instead of random math tricks SUBSCRIPTION INFORMATION Aritmo offers optional in-app purchases. The Basic Multiplication course is available in the app. The General Multiplication course requires an active subscription. Subscription availability and terms are shown clearly in the app before purchase and are managed through your Apple ID. You can use Aritmo to start learning mental multiplication techniques and upgrade only if you want access to the additional subscription course. Start training your mental math skills with Aritmo. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://melbot.com.br/privacy.html
Screenshots
Verdict
The clearest difference is in-app purchases: Doomsday calculator memory at none against Aritmo's 2. Doomsday calculator memory also leads on ads (none vs shown). Aritmo's advantage is update cadence (every 2 days vs every 8 days). On price, 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
Both are free to download. Aritmo sells 2 in-app purchases, starting at $3.99 per month. Doomsday calculator memory asks for nothing beyond the download.
Doomsday calculator memory ships an update every 8 days, Aritmo every 2 days. The most recent releases landed on October 9, 2026 and October 31, 2026 respectively.
| Parameter | Doomsday calculator memory | Aritmo |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) — better | — |
| Number of ratings | 1 — better | — |
| Update frequency | Every 8 days | Every 2 days — better |
| Ads | No — better | Yes |
| In-app purchases | No — better | Yes |
| Monetization | Free | — |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 17.6 | 16.0 — better |
| Further details — not scored | ||
| Size | 4 MB | 13 MB |
| Age rating | 4+ | 4+ |
| Developer | Joao Vianna | LUCCA EMMANUEL PINELI SIMOES LTDA |
In-app purchases
Doomsday calculator memory
No in-app purchases
Aritmo
- Aritmo Premium$3.991 Month
- Aritmo Yearly Premium Access$29.991 Year
Questions
Is Doomsday calculator memory free?
Is Aritmo free?
Do Doomsday calculator memory or Aritmo have ads?
Which is updated more often, Doomsday calculator memory or Aritmo?
Other comparisons















