# 测量工具 vs 空空鱼

The clearest difference is in-app purchases: 测量工具 at none against 空空鱼's 10. 测量工具 also leads on ratings volume (77 vs 3). 空空鱼's advantage is ads (none vs shown) and rating (5.0 vs 4.5). On price, review sentiment, update cadence and device support there is nothing between them.

Both are free to download. 空空鱼 sells 10 one-off in-app purchases. 测量工具 asks for nothing beyond the download.

空空鱼 holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: 测量工具 has 77 ratings behind it against 3, so its average is the more settled of the two. Written reviews complicate that: 84% of 测量工具's written reviews are positive against 81% of 空空鱼's, so the app with the better star average is not the one people write more warmly about.

测量工具 ships an update monthly, 空空鱼 every 3 weeks. The most recent releases landed on November 1, 2026 and October 27, 2026 respectively.

## The numbers

| Metric | 测量工具 | 空空鱼 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.5 (77 ratings)](https://appshunter.io/ios/app/id1113334130/reviews) | **[5.0 (3 ratings)](https://appshunter.io/ios/app/id6502636164/reviews)** |
| Number of ratings | **77** | 3 |
| Positive reviews | **84.0% of reviews** | 81.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | Yes | **No** |
| Update frequency | Monthly | **Every 3 weeks** |
| Monetization | Free with in-app purchases | — |
| Size | 55 MB | 102 MB |
| Requires iOS | **12.0** | 13.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 17+ |
| Developer | [飞剑 姚](https://appshunter.io/developer/1113334129) | [Hebei Heiya Technology Co., Ltd.](https://appshunter.io/developer/1513117911) |

## What reviewers say

### 测量工具

[App page](https://appshunter.io/ios/app/id1113334130)

This utility app offers a suite of measurement tools for your phone. It includes a ruler, protractor, noise meter, distance calculator, level, compass, and flashlight. Easily measure lengths, angles, sound levels, and more with convenient on-the-go tools.

**Highlights:** Ruler (metric/inch), Noise meter (decibel), Protractor (camera-based), Distance measurement, Level tool, Compass, Flashlight

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

**In-app purchases:** none


### 空空鱼

[App page](https://appshunter.io/ios/app/id6502636164)

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

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 首充送100泡泡币 | $0.99 | one-time |
| 30泡泡币 | $0.99 | one-time |
| 一个月会员 | $0.99 | one-time |
| 90泡泡币 | $0.99 | one-time |
| 160泡泡币 | $0.99 | one-time |
| 270个泡泡币 | $1.99 | one-time |
| VIP季度会员 | $1.99 | one-time |
| 480个泡泡币 | $2.99 | one-time |
| SVIP会员 | $3.99 | one-time |
| 1100个泡泡币 | $5.99 | one-time |


## Frequently asked questions

### Is 测量工具 free?

测量工具 is free to download, with no in-app purchases.

### Is 空空鱼 free?

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

### Which has better reviews, 测量工具 or 空空鱼?

空空鱼 is rated higher. 测量工具 averages 4.5 out of 5 from 77 ratings, while 空空鱼 averages 5.0 from 3 ratings.

### Do 测量工具 or 空空鱼 have ads?

测量工具 shows ads; 空空鱼 does not.

### Which is updated more often, 测量工具 or 空空鱼?

测量工具 ships an update monthly, and 空空鱼 every 3 weeks. Most recently, 测量工具 was updated on November 1, 2026 and 空空鱼 on October 27, 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.*