Is it Prime? vs InterCalc
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Is it Prime?
Enter any number to instantly determine if it is a prime number or not. This straightforward utility provides a quick answer to your mathematical curiosity.
- Prime number identification
- Simple number input
- Instant yes/no results
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This application serves only one function - to satisfy your curiosity when you wonder whether a given number is prime or not. You put in the number, it says yes or no. Really, that's all it does.
InterCalc
This app performs linear interpolation using a set of X-Y values to define a relationship. It can calculate values based on defined points, useful for tasks like converting pressure readings to fluid volumes in containers or performing simple unit conversions.
- Linear interpolation of X-Y values
- Defines arbitrary functions from data points
- Calculates fluid volume from pressure readings
- Performs unit conversions (e.g., temperature, speed)
- Supports custom data sets
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This application is designed to linearly interpolate a value given a set of X-Y values that define a relationship. The X-Y values can be as simple as two points that specify a simple line, or they can be a set of points that specifies an arbitrary function. One use of this program is to calculate the amount of fluid in a container given a pressure reading at the bottom of the tank. Typically this situation results in several pressure readings and corresponding volume ( gallons, liters ) readings as the tank is being filled. Once the pressure measuring device is so calibrated, pressure readings can then be converted to gallon or liter values. Other uses include simple conversions between Fahrenheit and Celsius, or between kph and mph.
Screenshots
Verdict
The clearest difference is rating: InterCalc at 5.0 against Is it Prime?'s 3.2. InterCalc also leads on update cadence (every 11 months vs every 74 months). Is it Prime?'s advantage is ratings volume (5 vs 1) and iOS requirement (15.0 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.
InterCalc holds the better App Store score, 5.0 against 3.2. That said, the two scores are not equally well evidenced: Is it Prime? has 5 ratings behind it against 1, so its average is the more settled of the two.
Is it Prime? ships an update every 74 months, InterCalc every 11 months. The most recent releases landed on October 23, 2026 and October 17, 2026 respectively.
| Parameter | Is it Prime? | InterCalc |
|---|---|---|
| Price | Free | Free |
| Rating | 3.2 (5 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 71.4% of reviews | — |
| Number of ratings | 5 — better | 1 |
| Update frequency | Every 74 months | Every 11 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.0 — better | 18.6 |
| Further details — not scored | ||
| Size | 1 MB | 1 MB |
| Age rating | 4+ | 4+ |
| Developer | Wismar | River Rock Logic |
Customer experience
Is it Prime?
InterCalc
In-app purchases
Is it Prime?
No in-app purchases
InterCalc
No in-app purchases
