ZeroClock零时钟 vs Delta Calc
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
ZeroClock零时钟
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Time deserves more than one look. ZeroClock is a collection of fullscreen clocks crafted for iPhone and iPad. Place it on your desk, nightstand, or living-room shelf and turn your screen into a quiet, beautiful expression of time. From translucent Liquid Glass and precise Swiss Dial to spatial Ripple, Living Orrery, warm Nixie Glow, and shape-shifting Flux, every clock has its own proportions, typography, motion, and color. Why you'll love ZeroClock: • 27 handcrafted fullscreen clocks • Multiple color collections for every theme • Layouts individually refined for iPhone and iPad • 12/24-hour time, date, and seconds controls • Keep Screen Awake for desk and bedside display • English and Simplified Chinese • No ads, no account, and no personal data collection Start with 6 free clocks. A single ZeroClock Pro purchase permanently unlocks the other 21 premium clocks and every color collection. No subscription. Make every glance at the time worth a second look.
Delta Calc
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.
- Calculate percent changes
- Solve for any variable in the formula
- Customizable decimal places
- Haptic feedback
- Fun animations
- Adjustable keyboard buttons
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A fast, easy, and fun-to-use percent change calculator. Now you can quickly calculate discounts, financial gains, and percent changes without having to use Excel, Google, or do the long math. Delta Calc can solve for any of the three values within the percent change formula. It solves for the a, b, or c value in the percent change formula ((b - a) / a) * 100 = c. Other features include: - Haptic feedback (can be disabled if desired) - Change the number of decimal places displayed in the result (from 0 to 10) - Fun animation when tapping the swap button (warning: could become addictive) - Delightful to tap number pad buttons - Enable and disable keyboard buttons Terms: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy: https://deltacalc.app/privacy Support: https://deltacalc.app/support
Screenshots
Verdict
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.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
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.
| Parameter | ZeroClock零时钟 | Delta Calc |
|---|---|---|
| Price | Free — better | $0.99 |
| Rating | — | 5.0 (2 ratings) — better |
| Number of ratings | — | 2 — better |
| Update frequency | Every 3 weeks | Every 3 days — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | — | Paid |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.6 — better | 17.6 |
| Further details — not scored | ||
| Size | 27 MB | 2 MB |
| Age rating | 4+ | 4+ |
| Developer | 昌飞 佘 | Stephen Coffey |
In-app purchases
ZeroClock零时钟
- Premium$1.99
Delta Calc
- Delta Calc Monthly$0.991 Month
- Delta Calc Yearly$4.991 Year
- Delta Calc Lifetime$9.99









