isPrime? vs Voltcraft VC
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
isPrime?
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It's a fast prime number checker.
Voltcraft VC
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Compatible with Voltcraft's VC-41 Series socket tester, the App allows the user to: • Stream data to iPhone or iPad internal memory, with real-time remote viewing • Adjust sample rate • Export data in Excel® format • Share data files directly from application • Take snapshots of the measurement area with the connected iPhone or iPad camera • Store over 15k readings with the VC-41 wireless datalogging module, for download to Phone or Tablet, with programmable datalogger file size
Screenshots
Verdict
The clearest difference is update cadence: Voltcraft VC at every 2 months against isPrime?'s every 16 months. Voltcraft VC also leads on iOS requirement (11.0 vs 15.0). On price, 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
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
isPrime? ships an update every 16 months, Voltcraft VC every 2 months. The most recent releases landed on November 4, 2026 and October 30, 2026 respectively.
| Parameter | isPrime? | Voltcraft VC |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 16 months | Every 2 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.0 | 11.0 — better |
| Further details — not scored | ||
| Size | 4 MB | 13 MB |
| Age rating | 4+ | 17+ |
| Developer | Omer Faruk Mesebuken | CEI Conrad Electronic International (HK) Limited |
In-app purchases
isPrime?
No in-app purchases
Voltcraft VC
No in-app purchases
