dnCalc vs SvenGallery
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
dnCalc
Perform amazing mathematical "experiences" to impress friends and colleagues. This app allows you to reveal secret numbers, ages, zodiac signs, and more, all without touching a calculator. It's easy to use, requires no memorization, and can be done with your eyes closed.
- Reveal secret numbers
- Peek at ages and zodiac signs
- Calculate birth day of week
- Create custom formulas
- Works offline
- Up to 5 participants
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Imagine... You are enjoying a lunch with friends and you suggest to perform a strange mathematical "experience". You ask for several volunteers to think of a special number, a birthday, the age of their best friend... You then ask them to multiply these numbers together, without you being able to see anything, then multiply the result by a special number that you previously wrote on a piece of paper, before the demonstration begins. Your friends give you orally the final result of these operations. You close your eyes and after a few seconds you reveal in the right order, the secret numbers of your friends! dnCalc will allow you to easily produce this little miracle that you can adapt according to your wishes and to he context. Your friends or colleagues will be asking what magical mathematical operation you mentally do to "extract" their numbers. Guaranteed to impress! • Very easy to do. A PDF document explains in details the procedure (which you can adapt). • Nothing to memorize. • Up to 5 people can be involved in the demonstration. • The spectators manipulate the calculator, you do not touch anything. • You can do this demonstration with your eyes closed. • No need for internet connection. • The trick is absolutely undetectable, nothing to find. • The effect is reproducible several times in a row. Many other cool features : • Force any number you need. • Compute and peek the age of your volunteer. • Compute and peek his zodiac signs (classic or Chinese). • Compute and peek his birth day of week. • Build your own forcing/peeking formulas! *** IMPORTANT *** If you have questions, do not ask them in the app's reviews, in order to preserve the secret. Send an email to dnCalc@moult.org. Thank you ! Alistair Crompton
SvenGallery
This app digitally recreates the classic Svengali card trick using images. Spectators select a photo, and all images in the gallery instantly transform into the chosen one, offering a modern magic illusion.
- Digital Svengali card trick reimagined
- Spectator selects any image
- Instantaneous image transformation
- Modern blend of magic and technology
- Dedicated image reveal system
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SvenGallery is a modern reimagination of the classic Svengali card trick. The spectator selects any image—whether through a force or their latest picture—and, in an instant, every photo in SvenGallery transforms into the same image. This seamless blend of timeless magic and cutting-edge technology brings the Svengali principle into the digital age, creating an unforgettable visual illusion. SvenGallery is a dedicated image reveal system within the Sven ecosystem. For magicians only. Not for laymen. Svengallery is a specialized magic app, not a traditional gallery, and is intended solely for performance and entertainment purposes.
Screenshots
Verdict
The clearest difference is update cadence: dnCalc at fortnightly against SvenGallery's every 4 months. dnCalc also leads on device support (3 vs 1) and iOS requirement (11.0 vs 18.6). On price, ads, in-app purchases and monetization model 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.
dnCalc ships an update fortnightly, SvenGallery every 4 months. The most recent releases landed on October 13, 2026 and September 27, 2026 respectively.
| Parameter | dnCalc | SvenGallery |
|---|---|---|
| Price | Free | Free |
| Rating | — | 5.0 (1 ratings) — better |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | — | 1 — better |
| Update frequency | Fortnightly — better | Every 4 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 11.0 — better | 18.6 |
| Further details — not scored | ||
| Size | 15 MB | 17 MB |
| Age rating | 4+ | 4+ |
| Developer | Devious-Monkey | Chetan Mehta |
Customer experience
dnCalc
SvenGallery
In-app purchases
dnCalc
No in-app purchases
SvenGallery
No in-app purchases









