PFD Calc vs Prime Not Prime
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
PFD Calc
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The app calculates prime factorization.
Prime Not Prime
A fast-paced game that combines number recognition with a swiping mechanic. Players swipe right for prime numbers and left for non-primes, aiming to build long streaks. It's designed to be both educational and entertaining, with leaderboards for competitive play.
- Addictive swiping gameplay
- Test prime number knowledge
- Build streaks and complete challenges
- Global leaderboards
- Vibrant visuals and animations
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Ready to swipe your way to prime number mastery? Prime Not Prime is the fun, fast-paced game where math meets swiping! Like Tinder for numbers, you swipe right for primes and left for everything else. Easy to learn, but can you handle the streak pressure? Features You’ll Love: • Addictive Swiping Gameplay: Swipe numbers left or right in a race against time. • Test Your Knowledge: Spot prime numbers and learn fun math facts. • Streaks and Challenges: Compete to see how long you can keep your streak alive. • Leaderboards: Challenge friends and global players to see who’s the prime master. • Widgets: Guess your prime numbers right from your Home Screen. • Fun Design: Vibrant visuals and satisfying animations make every swipe exciting. Whether you’re a math whiz or just love a challenge, Prime Not Prime is the ultimate game for your brain. Swipe, learn, and have fun with prime numbers! Privacy Policy & Terms: https://www.rspoon3.com/prime-not-prime/privacy/
Screenshots
Verdict
The clearest difference is ads: Prime Not Prime at none against PFD Calc's shown. PFD Calc's advantage is device support (3 vs 1) and iOS requirement (15.0 vs 17.0). On price, update cadence and in-app purchases 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. Neither carries in-app purchases, so what you see is what you pay.
PFD Calc ships an update every 5 weeks, Prime Not Prime monthly. The most recent releases landed on November 4, 2026 and October 30, 2026 respectively.
| Parameter | PFD Calc | Prime Not Prime |
|---|---|---|
| Price | Free | Free |
| Rating | — | 4.3 (6 ratings) — better |
| Positive reviews | — | 100.0% of reviews |
| Number of ratings | — | 6 — better |
| Update frequency | Every 5 weeks | Monthly — better |
| Ads | Yes | No — better |
| In-app purchases | No | No |
| Monetization | — | Free |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 15.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 14 MB | 15 MB |
| Age rating | 4+ | 4+ |
| Developer | Kazuhisa Kobayashi | Richard Witherspoon |
In-app purchases
PFD Calc
No in-app purchases
Prime Not Prime
No in-app purchases
Questions
Is PFD Calc free?
Is Prime Not Prime free?
Do PFD Calc or Prime Not Prime have ads?
Which is updated more often, PFD Calc or Prime Not Prime?
Other comparisons
