Emulates classic Hewlett Packard RPN scientific calculators from the 1970s. Experience the original HP-35, HP-45, and HP-21 models on your iPhone.
5.0(5 ratings)
Free
Best apps like RPN-25 CE
16+ similar apps compared and reviewed
3.7 avg rating
7 free apps
Updated August 2026
RPN is great, but it's not the only option. Explore 16+ similar apps for iPhone and iPad, each reviewed and rated by real users. Find free alternatives, premium upgrades, and hidden gems.
Top Alternatives to RPN
3.1(7 ratings)
FreeIn-App Purchases
This app is a scientific and programmable calculator designed for science and engineering, replicating the functionality of the HP-11C. It offers extensive features for finance, business, statistics, complex numbers, and unit conversions, with a programmable interface for custom calculations.
RCL-57 by Paul Novaes
Worth Considering
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0.0(0 ratings)
Free
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.
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4
RLM-10CX
Scientific Calculator
Free
This scientific calculator offers a comprehensive suite of tools for finance, business, statistics, and complex scientific calculations. It emulates a classic calculator while leveraging modern iOS device capabilities for ease of use and advanced functions.
Finance and Business calculationsDate and Time interval calculationsAdvanced Statistics and Curve Fitting
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free5
HP 15c Calculator
Official emulator of HP 15c
$14.99
Experience the official emulator of the legendary HP 15c scientific calculator. This app offers a redesigned interface and modern look while preserving the precision and reliability of the original. It features RPN input, matrix calculations, complex functions, and numerical integration for professionals and students.
Official HP 15c emulatorRPN (Reverse Polish Notation)Matrix calculations
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Plus42
Enhanced HP-42S Calc Simulator
$9.99
This advanced scientific calculator simulates the classic HP-42S RPN calculator with enhanced features. It offers algebraic expressions, unit conversions, directories for storage, a larger resizable display, financial functions, and 2D plotting with integral and root finding.
HP-42S RPN calculator simulationAlgebraic expressionsAttached units and conversions
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HP15C: Scientific Calculator
Classic Science Calc for you
$4.99
Relive the classic computing experience with a vintage scientific calculator. This app emulates a beloved 90s model, offering a nostalgic and functional tool for calculations.
Vintage scientific calculator emulationClassic 90s designFunctional for scientific calculations
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paid8
Free42
HP-42S Calculator Simulator
Free
This application is a faithful re-implementation of the HP-42S scientific calculator and its associated printer. It offers full functionality without requiring original HP ROM images and is an open-source project.
HP-42S calculator simulationHP-82240 printer simulationOpen source project
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Rule of Three Calculator
by Saran Dumronggittigule
Free
This utility app helps you solve problems involving ratios and proportions. It calculates an unknown number based on the relationship between two other known numbers.
Ratio calculationProportion solvingFinds unknown numbers
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小灵龙App
by 北京新中新诚通信息技术股份有限公司
Free
This app provides comprehensive mobile services for campus cards, including traditional card functions like consumption and authentication, enhanced with QR code capabilities. It offers features for managing your campus card, paying various campus fees, and booking campus facilities.
Campus card managementQR code functionalityCampus fee payments
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