# OB ToolBox vs AnthroCalcFetal

The clearest difference is update cadence: AnthroCalcFetal at every 5 days against OB ToolBox's every 3 weeks. OB ToolBox's advantage is iOS requirement (13.0 vs 15.1). 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.

OB ToolBox ships an update every 3 weeks, AnthroCalcFetal every 5 days. The most recent releases landed on July 20, 2026 and September 13, 2026 respectively.

## The numbers

| Metric | OB ToolBox | AnthroCalcFetal |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Every 5 days** |
| Monetization | Free | — |
| Size | 56 MB | 65 MB |
| Requires iOS | **13.0** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 12+ | 4+ |
| Developer | [Frederick Blair](https://appshunter.io/developer/1565667368) | [BC Children's Hospital](https://appshunter.io/developer/1521364756) |

## What reviewers say

### OB ToolBox

[App page](https://appshunter.io/ios/app/ob-toolbox/id1565667366)

This app offers a quick reference for essential medical values related to fetal growth, amniotic fluid, and Doppler indices. It includes calculators for preterm birth prediction, cesarean risk, and risk of stillbirth or miscarriage.

**Highlights:** Fetal growth reference values, Estimated fetal weight calculator, Amniotic fluid and Doppler indices, Bishop score reference, Preterm birth predictor, Cesarean risk calculator, Stillbirth and miscarriage risk calculators

**Features:** macOS Compatibility

**In-app purchases:** none


### AnthroCalcFetal

[App page](https://appshunter.io/ios/app/anthrocalcfetal/id6741048463)

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

**In-app purchases:** none


## Frequently asked questions

### Is OB ToolBox free?

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

### Is AnthroCalcFetal free?

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

### Do OB ToolBox or AnthroCalcFetal have ads?

Neither OB ToolBox nor AnthroCalcFetal shows ads.

### Which is updated more often, OB ToolBox or AnthroCalcFetal?

OB ToolBox ships an update every 3 weeks, and AnthroCalcFetal every 5 days. Most recently, OB ToolBox was updated on July 20, 2026 and AnthroCalcFetal on September 13, 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.*