# 139邮箱 vs 《单位换算器》

The clearest difference is update cadence: 139邮箱 at monthly against 《单位换算器》's every 19 months. 139邮箱 also leads on rating (4.6 vs 4.3) and ratings volume (103 vs 9). 《单位换算器》's advantage is review sentiment (100% vs 86%) and iOS requirement (11.0 vs 14.0). 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.

139邮箱 holds the better App Store score, 4.6 against 4.3. That said, the two scores are not equally well evidenced: 139邮箱 has 103 ratings behind it against 9, so its average is the more settled of the two. Written reviews complicate that: 86% of 139邮箱's written reviews are positive against 100% of 《单位换算器》's, so the app with the better star average is not the one people write more warmly about.

139邮箱 ships an update monthly, 《单位换算器》 every 19 months. The most recent releases landed on October 26, 2026 and October 23, 2026 respectively.

## The numbers

| Metric | 139邮箱 | 《单位换算器》 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.6 (103 ratings)](https://appshunter.io/ios/app/139/id474433226/reviews)** | [4.3 (9 ratings)](https://appshunter.io/ios/app/id506490585/reviews) |
| Number of ratings | **103** | 9 |
| Positive reviews | 86.1% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Monthly** | Every 19 months |
| Monetization | Free | — |
| Size | 189 MB | 8 MB |
| Requires iOS | 14.0 | **11.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 17+ | 4+ |
| Developer | [China Mobile Internet Company Limited](https://appshunter.io/developer/1612019289) | [Xin Zhou](https://appshunter.io/developer/505384440) |

## What reviewers say

### 139邮箱

[App page](https://appshunter.io/ios/app/139/id474433226)

This app offers a comprehensive email and cloud storage solution, allowing users to send and receive emails, back up phone data, and utilize AI-powered tools for enhanced productivity. It provides secure cloud storage, voice-to-text notes, and convenient bill checking.

**Highlights:** Email and cloud storage integration, AI-powered writing and summarization, Secure cloud backup for files and photos, Voice-to-text note-taking, Multi-account email management, One-click passwordless login, Bill and invoice management

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

**In-app purchases:** none


### 《单位换算器》

[App page](https://appshunter.io/ios/app/id506490585)

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

**In-app purchases:** none


## Frequently asked questions

### Is 139邮箱 free?

139邮箱 is free to download, with no in-app purchases.

### Is 《单位换算器》 free?

《单位换算器》 is free to download, with no in-app purchases.

### Which has better reviews, 139邮箱 or 《单位换算器》?

139邮箱 is rated higher. 139邮箱 averages 4.6 out of 5 from 103 ratings, while 《单位换算器》 averages 4.3 from 9 ratings.

### Do 139邮箱 or 《单位换算器》 have ads?

Neither 139邮箱 nor 《单位换算器》 shows ads.

### Which is updated more often, 139邮箱 or 《单位换算器》?

139邮箱 ships an update monthly, and 《单位换算器》 every 19 months. Most recently, 139邮箱 was updated on October 26, 2026 and 《单位换算器》 on October 23, 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.*