# ZeroClock零时钟 vs Altimeter Pro

The clearest difference is price: ZeroClock零时钟 at Free against Altimeter Pro's $1.99. Altimeter Pro's advantage is in-app purchases (none vs 1) and update cadence (every 3 days vs every 3 weeks). On ads and device support there is nothing between them.

ZeroClock零时钟 is free to download; Altimeter Pro costs $1.99 up front. ZeroClock零时钟 sells 1 one-off in-app purchase. Altimeter Pro asks for nothing beyond the download.

ZeroClock零时钟 ships an update every 3 weeks, Altimeter Pro every 3 days. The most recent releases landed on October 27, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | ZeroClock零时钟 | Altimeter Pro |
| --- | --- | --- |
| Price | **Free** | $1.99 |
| Rating | — | **[4.7 (20 ratings)](https://appshunter.io/ios/app/altimeter-pro-altitude-and-map/id6747575267/reviews)** |
| Number of ratings | — | **20** |
| Positive reviews | — | 86.4% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Every 3 days** |
| Monetization | — | Paid |
| Size | 28 MB | 29 MB |
| Requires iOS | 15.6 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [昌飞 佘](https://appshunter.io/developer/1574625447) | [海英 王](https://appshunter.io/developer/1802757012) |

## What reviewers say

### ZeroClock零时钟

[App page](https://appshunter.io/ios/app/zeroclock/id1574644243)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium | $0.99 | one-time |


### Altimeter Pro

[App page](https://appshunter.io/ios/app/altimeter-pro-altitude-and-map/id6747575267)

This app provides real-time altitude, air pressure, and oxygen concentration readings using GPS and phone sensors. It also features a high-precision compass, location tracking, and customizable themes for outdoor adventures. Core functions work offline.

**Highlights:** Real-time altitude measurement, Air pressure and oxygen concentration sensing, High-precision electronic compass, GPS coordinates and address lookup, Speed monitoring, Customizable app themes, Offline functionality

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

**In-app purchases:** none


## Frequently asked questions

### Is ZeroClock零时钟 free?

ZeroClock零时钟 is free to download, with in-app purchases available.

### Is Altimeter Pro free?

Altimeter Pro costs $1.99, with no in-app purchases.

### Do ZeroClock零时钟 or Altimeter Pro have ads?

Neither ZeroClock零时钟 nor Altimeter Pro shows ads.

### Which is updated more often, ZeroClock零时钟 or Altimeter Pro?

ZeroClock零时钟 ships an update every 3 weeks, and Altimeter Pro every 3 days. Most recently, ZeroClock零时钟 was updated on October 27, 2026 and Altimeter Pro on October 30, 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.*