ThetaCalc vs RCL
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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
Read full descriptionHide full description
ThetaCalc is a RPN (Reverse Polish Notation) calculator which can be extended by functions and equations programmed by the user in JavaScript.
RCL
This app faithfully recreates the TI-57 programmable calculator, offering its full scientific functions and programming capabilities. It includes a user manual, sample programs, and features like turbo speed and alphanumeric display.
- TI-57 recreation
- Scientific functions
- Programming capabilities
- User manual included
- Sample programs
- Turbo speed option
- Alphanumeric display option
Read full descriptionHide full description
RCL-57 is a complete and faithful recreation of the TI-57, one of the first programmable calculators. RCL-57 implements all the scientific functions and programming capabilities of the TI-57. In addition, it includes: * A complete user manual * Sample programs including Lunar Lander * Optional turbo speed and alphanumeric display * Listings of steps, registers and log * Saving and loading of programs * Sharing and importing of programs
Screenshots
Verdict
The clearest difference is update cadence: ThetaCalc at every 3 months against RCL's every 14 months. RCL's advantage is iOS requirement (15.1 vs 17.6). On price, review sentiment, ads and in-app purchases 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.
ThetaCalc ships an update every 3 months, RCL every 14 months. The most recent releases landed on June 1, 2026 and September 19, 2026 respectively.
| Parameter | ThetaCalc | RCL |
|---|---|---|
| Price | Free | Free |
| Rating | 4.3 (4 ratings) — better | — |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| Number of ratings | 4 — better | — |
| Update frequency | Every 3 months — better | Every 14 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad | iPhone, iPod |
| Requires iOS | 17.6 | 15.1 — better |
| Further details — not scored | ||
| Size | 1 MB | 2 MB |
| Age rating | 4+ | 4+ |
| Developer | Felix Stehli | Paul Novaes |
Customer experience
ThetaCalc
RCL
In-app purchases
ThetaCalc
No in-app purchases
RCL
No in-app purchases
