# Complex RPN Calculator vs Halcyon Calc Lite

The clearest difference is rating: Halcyon Calc Lite at 4.6 against Complex RPN Calculator's 3.9. Halcyon Calc Lite also leads on review sentiment (67% vs 52%) and update cadence (every 3 months vs every 5 months). Complex RPN Calculator's advantage is in-app purchases (none vs 3) and ads (none vs shown). On price, ratings volume, device support and iOS requirement there is nothing between them.

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

Halcyon Calc Lite holds the better App Store score, 4.6 against 3.9. Both are backed by a comparable volume of ratings — 24 and 15 respectively. Written reviews point the same way: 52% of Complex RPN Calculator's written reviews are positive against 67% of Halcyon Calc Lite's.

Complex RPN Calculator ships an update every 5 months, Halcyon Calc Lite every 3 months. The most recent releases landed on October 21, 2026 and November 1, 2026 respectively.

## The numbers

| Metric | Complex RPN Calculator | Halcyon Calc Lite |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.9 (24 ratings)](https://appshunter.io/ios/app/complex-rpn-calculator/id291826330/reviews) | **[4.6 (15 ratings)](https://appshunter.io/ios/app/halcyon-calc-lite/id408004888/reviews)** |
| Number of ratings | **24** | 15 |
| Positive reviews | 51.7% of reviews | **66.7% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 5 months | **Every 3 months** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 1 MB | 13 MB |
| Requires iOS | **16.4** | 16.6 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [John Coddington](https://appshunter.io/developer/291826333) | [Halcyon Touch Software](https://appshunter.io/developer/327064662) |

## What reviewers say

### Complex RPN Calculator

[App page](https://appshunter.io/ios/app/complex-rpn-calculator/id291826330)

This scientific calculator utilizes a four-level stack and natively handles complex numbers. It allows users to input and view numbers in both polar and rectangular formats, remembering its state and offering 10 memory locations.

**Highlights:** Complex number support, Four-level stack, Polar and rectangular formats, State persistence, 10 memory locations, Scientific calculations

**Features:** macOS Compatibility

**In-app purchases:** none

**What reviewers like**

- ✅ Great RPN functionality
- ✨ Complex number support
- 🆓 Free to use
- 🚫 No ads or in-app purchases
- 💻 Works on macOS

**What reviewers complain about**

- 🎨 SwiftUI design is ugly
- 🐌 Slow keyboard response
- 🖱️ Clunky operation
- 📉 Complex number operations limited
- ⚠️ Broken on newer iOS versions (historically)

**Reported bugs**

- Mutes other apps when used
- Slow keyboard response after update
- X^3 calculation incorrect for large imaginary numbers
- App crashes on opening/button press (historical iOS 9 issues)
- App starts upside down in landscape on iPad (historical iOS 8 issue)

**Requested features**

- Turn off key click sound
- Customize number display
- See the stack
- Fix slow entry response
- Fix imaginary number calculation (X^3)


### 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 |


## Frequently asked questions

### Is Complex RPN Calculator free?

Complex RPN Calculator is free to download, with no in-app purchases.

### Is Halcyon Calc Lite free?

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

### Which has better reviews, Complex RPN Calculator or Halcyon Calc Lite?

Halcyon Calc Lite is rated higher. Complex RPN Calculator averages 3.9 out of 5 from 24 ratings, while Halcyon Calc Lite averages 4.6 from 15 ratings.

### Do Complex RPN Calculator or Halcyon Calc Lite have ads?

Halcyon Calc Lite shows ads; Complex RPN Calculator does not.

### Which is updated more often, Complex RPN Calculator or Halcyon Calc Lite?

Complex RPN Calculator ships an update every 5 months, and Halcyon Calc Lite every 3 months. Most recently, Complex RPN Calculator was updated on October 21, 2026 and Halcyon Calc Lite on November 1, 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.*