# Halcyon Calc Lite vs RPNPro

The clearest difference is in-app purchases: RPNPro at none against Halcyon Calc Lite's 3. RPNPro also leads on ads (none vs shown) and rating (5.0 vs 4.7). Halcyon Calc Lite's advantage is update cadence (every 3 months vs every 37 months) and review sentiment (67% vs 50%). On price and device support there is nothing between them.

Both are free to download. Halcyon Calc Lite sells 3 one-off in-app purchases. RPNPro asks for nothing beyond the download.

RPNPro holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: Halcyon Calc Lite has 15 ratings behind it against 1, so its average is the more settled of the two. Written reviews complicate that: 67% of Halcyon Calc Lite's written reviews are positive against 50% of RPNPro's, so the app with the better star average is not the one people write more warmly about.

Halcyon Calc Lite ships an update every 3 months, RPNPro every 37 months. The most recent releases landed on October 15, 2026 and September 28, 2026 respectively.

## The numbers

| Metric | Halcyon Calc Lite | RPNPro |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.7 (15 ratings)](https://appshunter.io/ios/app/halcyon-calc-lite/id408004888/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/rpnpro/id603155368/reviews)** |
| Number of ratings | **15** | 1 |
| Positive reviews | **66.7% of reviews** | 50.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | **Every 3 months** | Every 37 months |
| Monetization | Free with in-app purchases | **Free** |
| Size | 13 MB | 1 MB |
| Requires iOS | 16.6 | **9.1** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Halcyon Touch Software](https://appshunter.io/developer/327064662) | [Felix Meier](https://appshunter.io/developer/603155771) |

## What reviewers say

### Halcyon Calc Lite

[App page](https://appshunter.io/ios/app/halcyon-calc-lite/id408004888)

This app is a powerful calculator for students and professionals, offering advanced features like symbolic expression manipulation, graphing, and statistical analysis. It supports real, complex, and integer numbers, matrices, and vectors, making it versatile for various mathematical tasks.

**Highlights:** Symbolic expression manipulation, Graphing of expressions, Matrix and vector calculations, Statistical analysis, Multiple number formats (decimal, hex, octal, binary), Over 225 built-in operations

**Features:** Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Directory And Unit Conversion Support | $0.99 | one-time |
| Programming Support | $1.99 | one-time |
| Larger Display Upgrade | $1.99 | one-time |


### RPNPro

[App page](https://appshunter.io/ios/app/rpnpro/id603155368)

This calculator utilizes Reverse Polish Notation (RPN) for input, mirroring the functionality of classic HP calculators. It features a four-level stack with X, Y, Z, and T registers, displaying the X register in decimal, hexadecimal, and binary.

**Highlights:** Reverse Polish Notation (RPN) input, Four-level stack (X, Y, Z, T registers), Decimal, hexadecimal, and binary display, Modeled after HP calculators, Designed for software engineers

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Halcyon Calc Lite free?

Halcyon Calc Lite is free to download, with in-app purchases available.

### Is RPNPro free?

RPNPro is free to download, with no in-app purchases.

### Which has better reviews, Halcyon Calc Lite or RPNPro?

RPNPro is rated higher. Halcyon Calc Lite averages 4.7 out of 5 from 15 ratings, while RPNPro averages 5.0 from 1 ratings.

### Do Halcyon Calc Lite or RPNPro have ads?

Halcyon Calc Lite shows ads; RPNPro does not.

### Which is updated more often, Halcyon Calc Lite or RPNPro?

Halcyon Calc Lite ships an update every 3 months, and RPNPro every 37 months. Most recently, Halcyon Calc Lite was updated on October 15, 2026 and RPNPro on September 28, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*