# O vs Syn9

The clearest difference is in-app purchases: O at none against Syn9's 6. O also leads on device support (3 vs 1) and iOS requirement (15.5 vs 18.0). Syn9's advantage is update cadence (every 5 days vs every 3 weeks). On price and ads there is nothing between them.

Both are free to download. Syn9 sells 6 in-app purchases, starting at $3.00 per month. O asks for nothing beyond the download.

O ships an update every 3 weeks, Syn9 every 5 days. The most recent releases landed on November 7, 2026 and November 9, 2026 respectively.

## The numbers

| Metric | O | Syn9 |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Every 5 days** |
| Size | 3 MB | 57 MB |
| Requires iOS | **15.5** | 18.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [O-TECH JAPAN](https://appshunter.io/developer/1219186631) | [Tomohiro Sekikawa](https://appshunter.io/developer/1670259539) |

## What reviewers say

### O

[App page](https://appshunter.io/ios/app/o-tech-shift/id1645042734)

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

**In-app purchases:** none


### Syn9

[App page](https://appshunter.io/ios/app/syn9/id6758545066)

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

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Plus | $3.00 | per month |
| Max | $6.99 | per month |
| Plus annual | $29.00 | per year |
| Light size | $1.99 | one-time |
| Regular size | $3.99 | one-time |
| Generous size | $7.99 | one-time |


## Frequently asked questions

### Is O free?

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

### Is Syn9 free?

Syn9 is free to download, with in-app purchases available.

### Do O or Syn9 have ads?

Neither O nor Syn9 shows ads.

### Which is updated more often, O or Syn9?

O ships an update every 3 weeks, and Syn9 every 5 days. Most recently, O was updated on November 7, 2026 and Syn9 on November 9, 2026.

---

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