Plus42

Name: Plus42
Price: 9.99 USD
Rating: 4.9 (76 reviews)
Author: Thomas Okken

By: Thomas Okken

Enhanced HP-42S Calc Simulator

Features & Capabilities

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.

User Growth & Download Statistics

App Education Programming Open Source Developer Tools

By:

Thomas Okken

Rating:

4.90

(76)

Version:

1.3.15 Last updated: 2026-05-05

Version code:

885258003

Creation date:

2022-04-28

Compatible devices:

Size:

11.45MB

Price:

9.99

URLs:

Website ,Privacy policy

Full description:

Source:

Apple Apps Store

Data ingested on:

2026-06-06

Compare stats and ranking:

Ranking

# 162,482 ▼ 291

For Developers

Monetize with App Pass Boost with Extension Booster

Contact the developer

Chrome-Stats does not own this Apple app. Please use these information below to contact the Apple app developer.

Developed by:

Thomas Okken

Apple Apps Store

https://apps.apple.com/us/app/plus42/id1597963622

Website:

https://thomasokken.com/plus42/

User Reviews

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

Cons

Recent reviews

Don’t waste your money!

by Ab*****, 2026-05-09

Once you use an RPN calculator, you will never go back. The HP-42S beats the HP Prime in layout and ease of use for most task, and the enhancements in this implementation is great. I love having the (enhanced) HP-42S always with me on my iPhone whenever I need a calculator.

by Ca*****, 2026-01-12

I’ve really like this calculator however lately there seems to be an issue with programming. I had a program for the sulfur to convert Celsius to Fahrenheit and vice versa but for some reason it doesn’t work anymore so 212 Fahrenheit should be 100 Celsius. it comes up with something like minus one point something to the power of 6000 I wonder what the issue is?