# Immunity Science vs Probiotics Guide.

The clearest difference is in-app purchases: Immunity Science at none against Probiotics Guide.'s 2. Immunity Science also leads on ads (none vs shown). Probiotics Guide.'s advantage is update cadence (every 2 weeks vs every 14 months). On price, device support and iOS requirement there is nothing between them.

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

Immunity Science ships an update every 14 months, Probiotics Guide. every 2 weeks. The most recent releases landed on October 3, 2026 and September 29, 2026 respectively.

## The numbers

| Metric | Immunity Science | Probiotics Guide. |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 14 months | **Every 2 weeks** |
| Size | 32 MB | 160 MB |
| Requires iOS | 13.0 | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Immunity Science, Inc.](https://appshunter.io/developer/1672160767) | [Olga Ivanova](https://appshunter.io/developer/1733570435) |

## What reviewers say

### Immunity Science

[App page](https://appshunter.io/ios/app/immunity-science/id1672160765)

**Features:** macOS Compatibility

**In-app purchases:** none


### 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 |


## Frequently asked questions

### Is Immunity Science free?

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

### Is Probiotics Guide. free?

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

### Do Immunity Science or Probiotics Guide. have ads?

Probiotics Guide. shows ads; Immunity Science does not.

### Which is updated more often, Immunity Science or Probiotics Guide.?

Immunity Science ships an update every 14 months, and Probiotics Guide. every 2 weeks. Most recently, Immunity Science was updated on October 3, 2026 and Probiotics Guide. on September 29, 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.*