NBack 3D vs Random Quiz
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
NBack 3D
This app challenges your memory by requiring you to count 3D shapes of specific colors. As the 'N' value increases, the difficulty escalates, testing your ability to recall past stimuli in a sequence.
- N-Back memory challenge
- 3D shape and color recognition
- Increasing difficulty levels
- Sequence memorization
- Cognitive skill enhancement
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The task is only to count the 3D shapes of the specified shape and color, but as the N of the N ‘Back increases, it becomes more difficult. *N’Back : The current answer matches the one from N steps earlier in the sequence. *1’Back 1 task1: count & memorize 2 task2: count & memorize 3 answer for task1 4 task3: count & memorize 5 answer for task2 6 task4: count & memorize : *2’Back 1 task1: count & memorize 2 task2: count & memorize 3 task3: count & memorize 4 answer for task1 5 task4: count & memorize 6 answer for task2 7 task5: count & memorize :
Random Quiz
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This app displays math problems at random.
Screenshots
Verdict
The clearest difference is in-app purchases: Random Quiz at none against NBack 3D's 1. Random Quiz also leads on update cadence (every 5 days vs every 10 months). On price, ads, 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. NBack 3D sells 1 one-off in-app purchase. Random Quiz asks for nothing beyond the download.
NBack 3D ships an update every 10 months, Random Quiz every 5 days. The most recent releases landed on October 20, 2026 and October 6, 2026 respectively.
| Parameter | NBack 3D | Random Quiz |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) — better | — |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 1 — better | — |
| Update frequency | Every 10 months | Every 5 days — better |
| Ads | Yes | Yes |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | — |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 15.6 | 15.0 — better |
| Further details — not scored | ||
| Size | 5 MB | 3 MB |
| Age rating | 4+ | 4+ |
| Developer | Yasuyoshi Ota | Katsuhiko Yao |
In-app purchases
NBack 3D
- Extend to 20'Back & Remove Ads$2.99
Random Quiz
No in-app purchases
