# Implicit Differentiation Cal vs AMSU

The clearest difference is update cadence: Implicit Differentiation Cal at every 9 months against AMSU's every 18 months. Implicit Differentiation Cal also leads on device support. On price, in-app purchases and iOS requirement there is nothing between them.

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

Implicit Differentiation Cal ships an update every 9 months, AMSU every 18 months. The most recent releases landed on September 18, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | Implicit Differentiation Cal | AMSU |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | — |
| Update frequency | **Every 9 months** | Every 18 months |
| Size | 24 MB | 34 MB |
| Requires iOS | 13.0 | 13.0 |
| Devices | **iPhone, iPod** | — |
| Age rating | 4+ | 4+ |
| Developer | [Ahmad Sattar](https://appshunter.io/developer/1458483953) | [Adaptive TechSoft](https://appshunter.io/developer/581730622) |

## What reviewers say

### Implicit Differentiation Cal

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

**Features:** macOS Compatibility

**In-app purchases:** none


### AMSU

[App page](https://appshunter.io/ios/app/amsu/id6472884408)

**In-app purchases:** none


## Frequently asked questions

### Is Implicit Differentiation Cal free?

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

### Is AMSU free?

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

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

Implicit Differentiation Cal ships an update every 9 months, and AMSU every 18 months. Most recently, Implicit Differentiation Cal was updated on September 18, 2026 and AMSU on October 10, 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.*