Sosu der vs Prime Nerd
Price, ratings, monetisation and update history for both games, side by side — with what reviewers say about each.
Sosu der
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This app is a quiz application that determines whether a number is prime or composite and swipes the correct answer. A prime number is a natural number greater than 1 that is not divisible by any other number except 1 and the number itself. For example, 2, 3, 5, and 7 are single-digit prime numbers. Composite numbers (composite numbers) are natural numbers greater than 1 that are not prime and are represented by the product of smaller natural numbers (e.g., 4 = 2 x 2, 6 = 2 x 3). Through this app, you can test your judgment and reflexes while having fun learning these mathematical concepts. ... How many two-digit, three-digit, and four-digit prime numbers do you know? Translated with www.DeepL.com/Translator (free version)
Prime Nerd
Tap prime numbers as they float across the screen within a time limit. This speed math game offers multiple difficulty levels, a combo system for score multipliers, and a training mode to hone your skills. Compete globally on the leaderboard and customize your challenge with digit selection.
- Identify prime numbers
- Timed challenges
- Global leaderboard
- Multiple difficulty levels
- Combo score multiplier
- Training mode
- Dark/Light theme
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Spot the prime numbers and tap them before time runs out — a simple but surprisingly deep speed math game. HOW TO PLAY Bubbles float across the screen showing numbers. Tap only the primes! You have 30 seconds — how many can you get right? Tapping a composite number counts as a miss, so think fast. FEATURES · Global Leaderboard — Submit your score and compete with players worldwide · 4 Difficulty Levels — EASY / NORMAL / HARD, plus a secret LEGEND mode to unlock · Digit Customization — Choose 1 to 5 digits. Bigger numbers = harder = higher points · Combo System — Chain correct taps to multiply your score · Training Mode — Practice without a timer and sharpen your prime sense · Dark / Light Theme — Easy on the eyes, day or night · Japanese / English supported WHO IS IT FOR? Anyone who loves math or numbers People looking for a quick mental workout Players who want to compete on leaderboards Anyone who wants to train focus and reaction speed A prime number is any integer greater than 1 that can only be divided by 1 and itself (2, 3, 5, 7, 11,13…). They seem familiar — until the numbers get big. That's the challenge. Watch a short video ad to enjoy 1 hour of ad-free play. So, what's your score?
Screenshots
Verdict
The clearest difference is update cadence: Prime Nerd at every 3 days against Sosu der's every 4 months. Sosu der's advantage is device support (3 vs 1) and iOS requirement (15.0 vs 17.0). On price, ads 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.
Sosu der ships an update every 4 months, Prime Nerd every 3 days. The most recent releases landed on October 17, 2026 and October 11, 2026 respectively.
| Parameter | Sosu der | Prime Nerd |
|---|---|---|
| Price | Free | Free |
| Positive reviews | — | 0.0% of reviews |
| Update frequency | Every 4 months | Every 3 days — better |
| Ads | Yes | Yes |
| In-app purchases | No | No |
| Monetization | — | Ad-supported |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 15.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 140 MB | 50 MB |
| Age rating | 4+ | 4+ |
| Developer | Hirobumi Onishi | Hiroki Sekimoto |
In-app purchases
Sosu der
No in-app purchases
Prime Nerd
No in-app purchases









