# 城市謎案 Case City vs OiO client

The clearest difference is update cadence: OiO client at every 3 weeks against 城市謎案 Case City's every 3 months. 城市謎案 Case City's advantage is iOS requirement (13.0 vs 15.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

城市謎案 Case City ships an update every 3 months, OiO client every 3 weeks. The most recent releases landed on October 11, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | 城市謎案 Case City | OiO client |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 3 weeks** |
| Size | 27 MB | 276 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 12+ | 4+ |
| Developer | [JingZhi Co., Ltd.](https://appshunter.io/developer/981874522) | [7 Hz Inc.](https://appshunter.io/developer/1588381704) |

## What reviewers say

### 城市謎案 Case City

[App page](https://appshunter.io/ios/app/case-city/id1466057703)

**In-app purchases:** none


### OiO client

[App page](https://appshunter.io/ios/app/oio-client/id6449966269)

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

**In-app purchases:** none


## Frequently asked questions

### Is 城市謎案 Case City free?

城市謎案 Case City is free to download, with no in-app purchases.

### Is OiO client free?

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

### Do 城市謎案 Case City or OiO client have ads?

Neither 城市謎案 Case City nor OiO client shows ads.

### Which is updated more often, 城市謎案 Case City or OiO client?

城市謎案 Case City ships an update every 3 months, and OiO client every 3 weeks. Most recently, 城市謎案 Case City was updated on October 11, 2026 and OiO client on October 24, 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.*