isPrime? vs Pixel Clock
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
isPrime?
Read full descriptionHide full description
It's a fast prime number checker.
Pixel Clock
Read full descriptionHide full description
Make time a little more playful with Pixel Clock - Grid, a landscape pixel clock for your desk, nightstand or wall. NEW: CYBER CITY Watch the time on a giant billboard in a living neon city, with flying traffic, rain, glowing windows and a cozy window view with a sill you can play with. Turn on Music Visualizer and the city pulses to the sound around you. Cyber City is a premium face: try it free for 24 hours, then unlock it forever with a one-time purchase. No subscription. CLASSIC (FREE) Animated pixel digits with customizable colors, backgrounds and themes, a moving RGB border, falling-digit transitions, heart balloons when you shake, and a weekday indicator. DUAL TIME (FREE) See a second time zone side by side, adjust its offset, and enjoy shatter-and-restore effects and a seconds progress bar. MAKE IT YOURS 12/24-hour time, seconds, date, weekday and battery display, in 13 languages. Works on iPhone and iPad. The microphone is used only for Music Visualizer. Sound is analyzed on your device and never recorded.
Screenshots
Verdict
The clearest difference is in-app purchases: isPrime? at none against Pixel Clock's 2. Pixel Clock's advantage is update cadence (weekly vs every 16 months). On price, ads, device support and iOS requirement 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
Both are free to download. Pixel Clock sells 2 one-off in-app purchases. isPrime? asks for nothing beyond the download.
isPrime? ships an update every 16 months, Pixel Clock weekly. Both last shipped on November 4, 2026.
| Parameter | isPrime? | Pixel Clock |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 16 months | Weekly — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.0 | 15.0 |
| Further details — not scored | ||
| Size | 4 MB | 100 MB |
| Age rating | 4+ | 4+ |
| Developer | Omer Faruk Mesebuken | YIMING SHI |
In-app purchases
isPrime?
No in-app purchases
Pixel Clock
- Cyber City 1-day TrialFree
- Cyber City – Unlock Forever$2.99
