# OBSERV 320 vs Invisible Diary

The clearest difference is in-app purchases: OBSERV 320 at none against Invisible Diary's 1. OBSERV 320 also leads on iOS requirement (16.6 vs 26.2). On price there is nothing between them.

Both are free to download. Invisible Diary sells 1 one-off in-app purchase. OBSERV 320 asks for nothing beyond the download.

## The numbers

| Metric | OBSERV 320 | Invisible Diary |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | — |
| Update frequency | Every 2 weeks | — |
| Size | 103 MB | 1 MB |
| Requires iOS | **16.6** | 26.2 |
| Devices | **iPad** | — |
| Age rating | 4+ | 4+ |
| Developer | [InnoFaith beauty sciences](https://appshunter.io/developer/583003631) | [Marcel Hecker](https://appshunter.io/developer/1816893041) |

## What reviewers say

### OBSERV 320

[App page](https://appshunter.io/ios/app/observ-320/id1438612246)

**In-app purchases:** none


### Invisible Diary

[App page](https://appshunter.io/ios/app/invisible-diary-mindfulness/id6760036113)

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Invisible Diary Full Version | $8.99 | one-time |


## Frequently asked questions

### Is OBSERV 320 free?

OBSERV 320 is free to download, with no in-app purchases.

### Is Invisible Diary free?

Invisible Diary is free to download, with in-app purchases available.

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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.*