Image Calculator vs ThetaCalc
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Image Calculator
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Simple calculator. You can see the calculation history. The number displayed on the calculator display can be saved. How to use Percent calculation 10% of 50 50 % 10 = 5 300 plus 10% of 300 300 + 10 % = 330 Subtract 20% of 100 to 100 100 - 20 % = 80 AC Delete all of the calculation. C Move the calculation back one step. ( The previous one is displayed, is displayed the next on input. ) Delete the last digit of the numbers. Swipe the calculator display sideways. ( Copy, Paste, Save ) Numbers on calculator display Tap calculator display. Swipe the row of setting buttons to the right to reveal the memory button. ( iPhone portrait orientation ) To edit the title of the saved numbers. Long press the title. It is calculated by the same calculation method as a general calculator.
ThetaCalc
This utility app provides a Reverse Polish Notation (RPN) calculator. Users can extend its functionality by programming custom functions and equations using JavaScript.
- Reverse Polish Notation (RPN) calculator
- User-programmable functions
- JavaScript equation support
- Extensible functionality
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ThetaCalc is a RPN (Reverse Polish Notation) calculator which can be extended by functions and equations programmed by the user in JavaScript.
Screenshots
Verdict
The clearest difference is update cadence: ThetaCalc at every 3 months against Image Calculator's every 50 months. 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.
Image Calculator ships an update every 50 months, ThetaCalc every 3 months. The most recent releases landed on October 19, 2026 and October 1, 2026 respectively.
| Parameter | Image Calculator | ThetaCalc |
|---|---|---|
| Price | Free | Free |
| Rating | — | 4.3 (4 ratings) — better |
| Positive reviews | — | 100.0% of reviews |
| Number of ratings | — | 4 — better |
| Update frequency | Every 50 months | Every 3 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | — | Free |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 17.0 — better | 17.6 |
| Further details — not scored | ||
| Size | 372 MB | 1 MB |
| Age rating | 4+ | 4+ |
| Developer | Tomoki Hagano | Felix Stehli |
In-app purchases
Image Calculator
No in-app purchases
ThetaCalc
No in-app purchases
