# Cerulean vs iSecretWorld

The clearest difference is update cadence: iSecretWorld at daily against Cerulean's every 2 months. iSecretWorld also leads on 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.

Cerulean ships an update every 2 months, iSecretWorld daily. The most recent releases landed on October 22, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | Cerulean | iSecretWorld |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (392 ratings)](https://appshunter.io/ios/app/cerulean/id1381352370/reviews)** | — |
| Number of ratings | **392** | — |
| Positive reviews | 85.5% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Daily** |
| Monetization | Free | — |
| Size | 48 MB | 24 MB |
| Requires iOS | 15.0 | **13.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [丹 张](https://appshunter.io/developer/1381352369) | [建华 姚](https://appshunter.io/developer/1788245287) |

## What reviewers say

### Cerulean

[App page](https://appshunter.io/ios/app/cerulean/id1381352370)

A collection of minimalist utility tools designed for simplicity and ease of use. Provides various small functions to help with everyday tasks. Feedback is welcomed for improvements and new ideas.

**Highlights:** Multiple utility tools, Minimalist design, Simple to use, User feedback welcome

**In-app purchases:** none

**What reviewers like**

- 👍 Very interesting and useful
- 👍 Great and free to use
- 👍 No ads, clean interface
- 👍 Very comprehensive toolset
- 👍 Good and simple

**What reviewers complain about**

- ❓ Limitation unclear, is it free?
- ❓ App is entirely in Chinese, no English option
- ❓ Ruler function has issues on iOS 17
- ❓ Volume is too low for sound-related features
- ❓ Search functionality is poor

**Reported bugs**

- Ruler function has issues on iOS 17
- Volume is too low for sound-related features (metronome, call simulation)
- Search functionality is poor
- Calculator button missing on iPad Pro
- Ruler is inaccurate on 12 mini

**Requested features**

- Add more small features
- Add currency conversion function
- Add data and Chinese uppercase number conversion
- Consider adding various unit conversion functions


### iSecretWorld

[App page](https://appshunter.io/ios/app/isecretworld/id6768144048)

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

**In-app purchases:** none


## Frequently asked questions

### Is Cerulean free?

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

### Is iSecretWorld free?

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

### Do Cerulean or iSecretWorld have ads?

Neither Cerulean nor iSecretWorld shows ads.

### Which is updated more often, Cerulean or iSecretWorld?

Cerulean ships an update every 2 months, and iSecretWorld daily. Most recently, Cerulean was updated on October 22, 2026 and iSecretWorld on October 10, 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.*