# Plus42

> Enhanced HP-42S Calc Simulator

Canonical page: [https://chrome-stats.com/d/id1597963622](https://chrome-stats.com/d/id1597963622)

## Overview

- **ID:** `id1597963622`
- **Platform:** Apple
- **Type:** Apple app
- **Status:** Available
- **Publisher:** Thomas Okken
- **Category:** Utilities
- **Rating:** 4.90 / 5 (79 ratings)
- **Version:** 1.3.15
- **Last updated:** 2026-05-05
- **First published:** 2022-04-28
- **Size:** 11 MB
- **Data as of:** 2026-09-06
- **Store listing:** [Apple App Store](https://apps.apple.com/us/app/plus42/id1597963622)
- **Website:** [https://thomasokken.com/plus42/](https://thomasokken.com/plus42/)
- **Privacy policy:** [https://thomasokken.com/plus42/privacy.html](https://thomasokken.com/plus42/privacy.html)

## Description

Plus42 is an advanced scientific programmable calculator based on Free42, a complete re-implementation of the HP-42S. It preserves the HP-42S capabilities while extending them with modern features and a Chrome-friendly interface.

Key enhancements include algebraic expressions similar to HP-27S/HP-17B/19B, attached units and conversions, organized program and variable storage, a larger resizable display, money-time value calculations, amortization schedules, and 2D plotting with zoom, pan, and integral/root-from-plot-point support.

## Rankings

- #144,441 — Overall

## Review summary

Plus42 is widely praised for faithfully recreating the HP-42S RPN calculator on iPhone and iPad, delivering nostalgic fidelity, portability, and a polished, feature-rich experience that surpasses Free42. Reviewers value its faithful feel, the ability to have a powerful calculator in their pocket, and the strong graphics/UI. Many call it the best HP-inspired calculator app. Some note a programming issue, iPad multitasking limitations, and requests for more programming capabilities (e.g., TVM variables). Overall, user sentiment is highly positive with occasional feature requests.

### Pros

- Faithful HP-42S recreation with nostalgic fidelity
- Portable/mobile access: always with you on iPhone/iPad
- Rich feature set and enhancements (e.g., Dir and Eqn)
- Beautiful, polished graphics and UI
- Intuitive and easy to use for RPN users

## Similar extensions and apps

- [Free42](https://chrome-stats.com/d/id337692629) — 4.80 / 5
- [DB40X](https://chrome-stats.com/d/id6624315901) — 4.70 / 5
- [RPN-45 SD](https://chrome-stats.com/d/id509923051) — 4.30 / 5
- [i41CX](https://chrome-stats.com/d/id292619450) — 4.60 / 5
- [i41CX+](https://chrome-stats.com/d/id289068865) — 4.80 / 5
- [DB48X](https://chrome-stats.com/d/id6615086535) — 4.80 / 5
- [R47 RPN Calculator](https://chrome-stats.com/d/id6763615664) — 5.00 / 5
- [RPN-34 CE](https://chrome-stats.com/d/id1448593029) — 5.00 / 5
- [DB50X](https://chrome-stats.com/d/id6625971367) — 5.00 / 5
- [RPN-32 CE](https://chrome-stats.com/d/id1082637146) — 5.00 / 5
- [Calculator 42 with History PRO](https://chrome-stats.com/d/id1525901717) — 4.60 / 5
- [Scientific Calculator Plus 991](https://chrome-stats.com/d/id1449106995) — 4.70 / 5

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Source: [Chrome-Stats](https://chrome-stats.com/d/id1597963622)