# Probiotics Guide. vs Dirac equation

The clearest difference is in-app purchases: Dirac equation at none against Probiotics Guide.'s 2. Dirac equation also leads on ads (none vs shown). Probiotics Guide.'s advantage is iOS requirement (13.0 vs 17). On price and device support there is nothing between them.

Both are free to download. Probiotics Guide. sells 2 in-app purchases, starting at $1.99 per month. Dirac equation asks for nothing beyond the download.

## The numbers

| Metric | Probiotics Guide. | Dirac equation |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 2 weeks | — |
| Size | 160 MB | 5 MB |
| Requires iOS | **13.0** | 17 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Olga Ivanova](https://appshunter.io/developer/1733570435) | [Sungjun Kim](https://appshunter.io/developer/1602461985) |

## What reviewers say

### Probiotics Guide.

[App page](https://appshunter.io/ios/app/probiotics-guide/id6720753184)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Subscription | $1.99 | per month |
| Sponsorship | $1.99 | one-time |


### Dirac equation

[App page](https://appshunter.io/ios/app/dirac-equation/id6739155551)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Probiotics Guide. free?

Probiotics Guide. is free to download, with in-app purchases available.

### Is Dirac equation free?

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

### Do Probiotics Guide. or Dirac equation have ads?

Probiotics Guide. shows ads; Dirac equation does not.

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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.*