# NIE Library vs Implicit Differentiation Cal

The clearest difference is update cadence: Implicit Differentiation Cal at every 9 months against NIE Library's every 21 months. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

NIE Library ships an update every 21 months, Implicit Differentiation Cal every 9 months. The most recent releases landed on October 1, 2026 and September 18, 2026 respectively.

## The numbers

| Metric | NIE Library | Implicit Differentiation Cal |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 21 months | **Every 9 months** |
| Size | 32 MB | 24 MB |
| Requires iOS | 13.4 | **13.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [National Institute of Education (NIE) Singapore](https://appshunter.io/developer/426893549) | [Ahmad Sattar](https://appshunter.io/developer/1458483953) |

## What reviewers say

### NIE Library

[App page](https://appshunter.io/ios/app/nie-library/id513175751)

**Features:** macOS Compatibility

**In-app purchases:** none


### Implicit Differentiation Cal

[App page](https://appshunter.io/ios/app/implicit-differentiation-cal/id1607963477)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is NIE Library free?

NIE Library is free to download, with no in-app purchases.

### Is Implicit Differentiation Cal free?

Implicit Differentiation Cal is free to download, with no in-app purchases.

### Do NIE Library or Implicit Differentiation Cal have ads?

Neither NIE Library nor Implicit Differentiation Cal shows ads.

### Which is updated more often, NIE Library or Implicit Differentiation Cal?

NIE Library ships an update every 21 months, and Implicit Differentiation Cal every 9 months. Most recently, NIE Library was updated on October 1, 2026 and Implicit Differentiation Cal on September 18, 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.*