# Sandbook vs Open Invite

The clearest difference is in-app purchases: Sandbook at none against Open Invite's 3. Sandbook also leads on update cadence (weekly vs every 7 months) and iOS requirement (18.2 vs 26.0). On price, ads and device support there is nothing between them.

Both are free to download. Open Invite sells 3 one-off in-app purchases. Sandbook asks for nothing beyond the download.

Sandbook ships an update weekly, Open Invite every 7 months. Both last shipped on October 28, 2026.

## The numbers

| Metric | Sandbook | Open Invite |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.6 (135 ratings)](https://appshunter.io/ios/app/sandbook-natural-voice-reader/id6745732885/reviews)** | — |
| Number of ratings | **135** | — |
| Positive reviews | 80.6% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Weekly** | Every 7 months |
| Monetization | Free | — |
| Size | 140 MB | 7 MB |
| Requires iOS | **18.2** | 26.0 |
| Devices | **iPhone, iPad, Mac** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [SmashMelon LLC](https://appshunter.io/developer/1895995887) | [Christian Tietze](https://appshunter.io/developer/581693527) |

## What reviewers say

### Sandbook

[App page](https://appshunter.io/ios/app/sandbook-natural-voice-reader/id6745732885)

This app converts text into natural-sounding speech using an on-device model. Read ePub, PDF, and TXT files, type or paste text, or even read webpages aloud. Export audio files for offline listening with complete privacy.

**Highlights:** On-device text-to-speech, Reads ePub, PDF, TXT files, Type or paste text, Read webpages aloud, Export audio files, Privacy protection

**Features:** Vision Pro support

**In-app purchases:** none


### Open Invite

[App page](https://appshunter.io/ios/app/open-invite/id6757206056)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Thank You | $0.99 | one-time |
| Appreciation Tip | $2.99 | one-time |
| Showing Support | $4.99 | one-time |


## Frequently asked questions

### Is Sandbook free?

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

### Is Open Invite free?

Open Invite is free to download, with in-app purchases available.

### Do Sandbook or Open Invite have ads?

Neither Sandbook nor Open Invite shows ads.

### Which is updated more often, Sandbook or Open Invite?

Sandbook ships an update weekly, and Open Invite every 7 months. Most recently, Sandbook was updated on October 28, 2026 and Open Invite on October 28, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*