# Implicit Differentiation Cal vs The BALM Primer App

The clearest difference is update cadence: Implicit Differentiation Cal at every 9 months against The BALM Primer App's every 41 months. Implicit Differentiation Cal also leads on iOS requirement (13.0 vs 15.6). 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.

Implicit Differentiation Cal ships an update every 9 months, The BALM Primer App every 41 months. Both last shipped on November 7, 2026.

## The numbers

| Metric | Implicit Differentiation Cal | The BALM Primer App |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 9 months** | Every 41 months |
| Size | 24 MB | 19 MB |
| Requires iOS | **13.0** | 15.6 |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 4+ | 17+ |
| Developer | [Ahmad Sattar](https://appshunter.io/developer/1458483953) | [The BALM LLC](https://appshunter.io/developer/1660892512) |

## What reviewers say

### Implicit Differentiation Cal

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

**Features:** macOS Compatibility

**In-app purchases:** none


### The BALM Primer App

[App page](https://appshunter.io/ios/app/the-balm-primer-app/id1660892510)

**Features:** macOS Compatibility

**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 The BALM Primer App free?

The BALM Primer App is free to download, with no in-app purchases.

### Do Implicit Differentiation Cal or The BALM Primer App have ads?

Neither Implicit Differentiation Cal nor The BALM Primer App shows ads.

### Which is updated more often, Implicit Differentiation Cal or The BALM Primer App?

Implicit Differentiation Cal ships an update every 9 months, and The BALM Primer App every 41 months. Most recently, Implicit Differentiation Cal was updated on November 7, 2026 and The BALM Primer App on November 7, 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.*