# N4 vs Uncertainty Calculator

The clearest difference is price: Uncertainty Calculator at $3.99 against N4's $9.99. Uncertainty Calculator also leads on iOS requirement (17.0 vs 26.0). On update cadence, ads, in-app purchases and monetization model there is nothing between them.

N4 costs $9.99 and Uncertainty Calculator $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

N4 ships an update every 6 months, Uncertainty Calculator every 3 months. The most recent releases landed on September 20, 2026 and September 14, 2026 respectively.

## The numbers

| Metric | N4 | Uncertainty Calculator |
| --- | --- | --- |
| Price | $9.99 | **$3.99** |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/uncertainty-calculator/id1170905440/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 6 months | **Every 3 months** |
| Monetization | Paid | Paid |
| Size | 19 MB | 1 MB |
| Requires iOS | 26.0 | **17.0** |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Yamase & Touwa Japanese Insititute](https://appshunter.io/developer/442115304) | [Roman Volinsky](https://appshunter.io/developer/977951850) |

## What reviewers say

### N4

[App page](https://appshunter.io/ios/app/n4/id495496641)

Master JLPT N4 grammar with this app. It organizes sentence patterns with clear explanations in Chinese and provides practice questions. Easily mark difficult words for review to improve your exam performance.

**Highlights:** JLPT N4 grammar organization, Detailed sentence pattern explanations, Chinese language explanations, Word marking for review, Over 300 practice questions

**Features:** Vision Pro support

**In-app purchases:** none


### Uncertainty Calculator

[App page](https://appshunter.io/ios/app/uncertainty-calculator/id1170905440)

This app allows users to perform error propagation calculations for mathematical expressions involving uncertain variables. It supports absolute and relative error inputs, various functions, and trigonometric calculations in degrees or radians. The tool helps ensure accurate reporting of results based on estimated errors.

**Highlights:** Error propagation calculations, Absolute and relative error input, Support for mathematical functions, Trigonometric calculations (degrees/radians), Variable combination in expressions, Significant figure guidance

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is N4 free?

N4 costs $9.99, with no in-app purchases.

### Is Uncertainty Calculator free?

Uncertainty Calculator costs $3.99, with no in-app purchases.

### Do N4 or Uncertainty Calculator have ads?

Neither N4 nor Uncertainty Calculator shows ads.

### Which is updated more often, N4 or Uncertainty Calculator?

N4 ships an update every 6 months, and Uncertainty Calculator every 3 months. Most recently, N4 was updated on September 20, 2026 and Uncertainty Calculator on September 14, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*