Just A Calc vs PrimeCalc
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Just A Calc
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This is Just A Calculator, nothing more, nothing less. The calculator will perform addition, subtraction, multiplication, division, percentage calculations, and find the square root. This will allow a maximum 38 digits to the left of the decimal and a maximum of 12 digits to the right of the decimal. This was developed primarily for the iPhone, however it will work on any iOS device.
PrimeCalc
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--- PrimeCalc feature --- ■ Normal arithmetic operation (×, /, +, -) is available. ■ prime: integer calculation (Division remainder ÷, prime factorization p) can be done. (You can also exponentiate.) ■ auto: Automatic calculation, memory storage, history recording is possible. ■ global: Digit display of countries around the world is possible. （千、万、億、兆、京、垓、・・・） ■ iPhone / iPad is available. Free. We are displaying advertisements. Caution) In case of large number, calculation error etc. may occur. Please use it together with other calculator. If you have comments, questions, etc., please email or bulletin board. http: //www.eonet.ne.jp/~treechart/
Screenshots
Verdict
The clearest difference is ads: Just A Calc at none against PrimeCalc's shown. PrimeCalc's advantage is update cadence (every 5 weeks vs every 38 months). On price, in-app purchases, 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. Neither carries in-app purchases, so what you see is what you pay.
Just A Calc ships an update every 38 months, PrimeCalc every 5 weeks. The most recent releases landed on September 9, 2026 and September 10, 2026 respectively.
| Parameter | Just A Calc | PrimeCalc |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 38 months | Every 5 weeks — better |
| Ads | No — better | Yes |
| In-app purchases | No | No |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 12.0 | 12.0 |
| Further details — not scored | ||
| Size | 10 MB | 12 MB |
| Age rating | 4+ | 4+ |
| Developer | Tom Doherty | Yutaka Nakao |
In-app purchases
Just A Calc
No in-app purchases
PrimeCalc
No in-app purchases
Questions
Is Just A Calc free?
Is PrimeCalc free?
Do Just A Calc or PrimeCalc have ads?
Which is updated more often, Just A Calc or PrimeCalc?
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