SigiCalc vs Find Prime Num
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
SigiCalc
This app provides a graphical RPN calculator with an undo feature. Users can input mathematical equations and instantly visualize them with a plot. It's designed for simplicity and practicality in mathematical calculations.
- Graphical RPN calculator
- Equation plotting
- Undo functionality
- Simple interface
- Practical calculations
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SigiCalc is a fast, clean RPN calculator that draws your functions. Enter a calculation the RPN way – numbers first, then the operation – and as soon as your expression contains X, tap Graph to see it plotted. No equals key, no parentheses, no fuss. REAL RPN • Classic stack-based entry with Enter, Undo and All Clear • Keys light up only when the stack has enough values – you can't make an invalid entry • The display shows your result, the whole expression in normal notation and the raw stack LIVE FUNCTION GRAPHS • Use X as a variable and plot the result instantly • Pinch to zoom, drag to pan, tap to zoom in, double-tap to reset • Touch and hold to read the exact x / y value on the curve • Discontinuities like tan(x) or 1/x are drawn correctly – no misleading vertical lines SCIENTIFIC FUNCTIONS sin, cos, tan and their inverses, natural log, square, square root, reciprocal, sign change and π DESIGNED FOR TODAY'S DEVICES • Light and Dark Mode, portrait and landscape • iPad: calculator and live graph side by side • Smooth animations and haptic feedback PRIVATE BY DESIGN SigiCalc works entirely on your device. No account, no network, no ads, no tracking. Example: X ↲ X sin × plots x · sin(x). What changed versus your text and why: - Leads with a benefit, not a category: "draws your functions" is the hook; "simple and practical graphical" told the reader nothing they'd search for. - Explains RPN in one sentence for people who don't know it, since that's the biggest reason someone bounces. - Bulleted feature blocks — App Store descriptions are skimmed, and the capitalised headings scan well in the store's plain-text rendering. - Adds Dark Mode / iPad / privacy, all of which are new in 3.0 and are things reviewers and users look for. - Fixed "polish" → "Polish" and "equation" → "expression" (you plot expressions, not equations).
Find Prime Num
Quickly determine if a number is prime and find one of its factors. This app also measures calculation time to help you benchmark your device's processing speed. Share your results and compare performance with others.
- Calculate prime numbers up to 64-bit integers
- Measure processing time for device speed comparison
- Find one factor of a non-prime number
- Share calculation results
- User-friendly interface
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Do you want to find out if a number if a prime number? Are you constantly spending hours to calculate if a long number is prime? If the answer is yes for any of these questions, you should download "Find Prime Num" app. "Find Prime Num" allows you to find out if a number is a prime or not. It will also give you a factor of this number. In addition, it will tell you how long it takes for the app to calculate, which indicates how fast your device is. You can use this value to test your device's processing speed against other devices. "Find Prime Num" is an app for you to find out if your number is prime. It can be used on iPhone, iPod Touch and iPad. It is simple, easy to use, and very informative. You can share your results with others as well. Main Features ◉ Calculate prime number up to 64-bit integer ◉ Calculate the processing time, an indicator of the speed of the CPU of your device ◉ Calculate one factor of your number if it isn't a prime ◉ Share your results with others to see whose devices are faster ◉ User-friendly interface
Screenshots
Verdict
The clearest difference is update cadence: Find Prime Num at every 4 days against SigiCalc's every 48 months. Find Prime Num also leads on iOS requirement (12.0 vs 17.0). On price, rating, review sentiment and ratings volume 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.
On the App Store both sit at effectively the same score — 5.0 for SigiCalc against 5.0 for Find Prime Num. Both are backed by a comparable volume of ratings — 1 and 1 respectively. Written reviews split almost evenly too, at 50% and 50% positive.
SigiCalc ships an update every 48 months, Find Prime Num every 4 days. The most recent releases landed on November 1, 2026 and November 3, 2026 respectively.
| Parameter | SigiCalc | Find Prime Num |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) | 5.0 (1 ratings) |
| Positive reviews | 50.0% of reviews | 50.0% of reviews |
| Number of ratings | 1 | 1 |
| Update frequency | Every 48 months | Every 4 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 17.0 | 12.0 — better |
| Further details — not scored | ||
| Size | 3 MB | 8 MB |
| Age rating | 4+ | 4+ |
| Developer | Siegware | Duo Pisceses, Inc. |
Customer experience
SigiCalc
Find Prime Num
In-app purchases
SigiCalc
No in-app purchases
Find Prime Num
No in-app purchases
Questions
Is SigiCalc free?
Is Find Prime Num free?
Which has better reviews, SigiCalc or Find Prime Num?
Do SigiCalc or Find Prime Num have ads?
Which is updated more often, SigiCalc or Find Prime Num?
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