# ZeroClock零时钟 vs Delta Calc

The clearest difference is price: ZeroClock零时钟 at Free against Delta Calc's $0.99. ZeroClock零时钟 also leads on iOS requirement (15.6 vs 17.6). Delta Calc's advantage is update cadence (every 3 days vs every 3 weeks). On ads, in-app purchases and device support there is nothing between them.

ZeroClock零时钟 is free to download; Delta Calc costs $0.99 up front. ZeroClock零时钟 sells 1 one-off in-app purchase and Delta Calc sells 3 in-app purchases, starting at $0.99 per month. Whichever you choose, the download price is not the number that matters.

ZeroClock零时钟 ships an update every 3 weeks, Delta Calc every 3 days. The most recent releases landed on October 10, 2026 and October 17, 2026 respectively.

## The numbers

| Metric | ZeroClock零时钟 | Delta Calc |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| Rating | — | **[5.0 (2 ratings)](https://appshunter.io/ios/app/delta-calc/id6504148868/reviews)** |
| Number of ratings | — | **2** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Every 3 days** |
| Monetization | — | Paid |
| Size | 27 MB | 2 MB |
| Requires iOS | **15.6** | 17.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [昌飞 佘](https://appshunter.io/developer/1574625447) | [Stephen Coffey](https://appshunter.io/developer/1723308273) |

## 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 | $1.99 | one-time |


### Delta Calc

[App page](https://appshunter.io/ios/app/delta-calc/id6504148868)

Quickly calculate percent changes, discounts, and financial gains without complex math. Solve for any of the three values in the percent change formula with an intuitive interface and fun animations.

**Highlights:** Calculate percent changes, Solve for any variable in the formula, Customizable decimal places, Haptic feedback, Fun animations, Adjustable keyboard buttons

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Delta Calc Monthly | $0.99 | per month |
| Delta Calc Yearly | $4.99 | per year |
| Delta Calc Lifetime | $9.99 | one-time |


## Frequently asked questions

### Is ZeroClock零时钟 free?

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

### Is Delta Calc free?

Delta Calc costs $0.99, and also offers in-app purchases.

### Do ZeroClock零时钟 or Delta Calc have ads?

Neither ZeroClock零时钟 nor Delta Calc shows ads.

### Which is updated more often, ZeroClock零时钟 or Delta Calc?

ZeroClock零时钟 ships an update every 3 weeks, and Delta Calc every 3 days. Most recently, ZeroClock零时钟 was updated on October 10, 2026 and Delta Calc on October 17, 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.*