Comparison

WP 31s vs RLM

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

WP 31s

This app emulates a classic RPN scientific calculator, offering a rich function set for daily use with a simplified interface. It's based on the more complex WP 34s but is designed for easier operation.

Highlights
  • RPN scientific calculator emulation
  • Rich function set
  • Simplified, less cluttered keyboard
  • Based on WP 34s
  • Available on iOS
Features
Read full description

WP 31s is a classic RPN scientific calculator based on the powerful but more complex WP 34s. Now available on iOS too (see the support site for other emulators and for the real stuff). It is not programmable but has a rich function set for daily use and is easier to use, thanks to a less cluttered keyboard. A manual can be downloaded at http://sourceforge.net/projects/wp34s/files/doc/Manual_wp_31s_1_2q.pdf/download

About

RLM

This app offers a comprehensive suite of financial, business, scientific, and statistical calculators. It includes specialized worksheets for loan amortization, bond pricing, currency exchange, probability distributions, and complex number operations. Users can also perform date and time calculations, solve arbitrary equations, and convert units.

Highlights
  • Finance worksheets (amortization, bonds, options)
  • Business tools (bill split, break-even, currency)
  • Statistical analysis (probability, regressions)
  • Scientific functions (complex numbers, vectors)
  • Unit and currency conversions
  • Equation solver
  • Date and time calculations
Features
Read full description

The RLM-19BII is a general purpose calculator with a special focus in finance, business and science. It is designed to bring up the most of your iOS devices with an extensive set of worksheets and enhancements to cover most of the functions generally needed by financial, business, mathematical, engineering and scientific professionals. >Finance Worksheets: •Account Balance: Calculates the Balance of cash transactions and interest applied at arbitrary dates. •Amortization: Loan Amortization Schedule for a single or several loan payments. •Bond Price & Yield: Calculates the Price, Yield and Effective Duration of a Bond. •Black-Scholes Options: Calculates the CALL, PUT and “Greeks” values of a Black-Scholes European option. •Depreciation: Calculates depreciation with SL, SOYD, DB or MACRS methods and conventions. •Time Value of Money: Calculates compound Interest problems. >Business Worksheets: •Bill-Tip-Split: Calculates the sharing of a Bill with Tip. •Break-Even: Analyze the following relation: Profit = (Price - Var.Cost) • Units - Fix.Cost •Currency Exchange with manual or on-line rates. •Percents & Margins: Calculates %Change, %Total and Business margins. >Cash Flows Worksheets: •Equal Periods: Calculations with Cash Flows occurring at regular time intervals. •Unequal Periods: Calculations with Cash Flows occurring at arbitrary dates. >Statistics Worksheets: •Probability: Combinations, permutations and Normal, Exponential, t-Student and Weibull probability distributions. •One-Variable Statistics: Calculations for one variable data samples. •Two-Variable Statistics: Calculations for two variables data samples. •Curve Fitting: Regression models to fit a curve based on two variables data samples. >Scientific Worksheets: •Complex Numbers: Operations and functions with complex numbers. •Logarithms, Trigonometric, Hyperbolic and Number Alteration functions. •Triangle Solution: Solves a Plane & Spherical triangles. •3D Vectors: Operations and functions with vectors in Cartesian, Spherical or Cylindrical coordinates. •Universal Constants: All the NIST-CODATA physical constants values and descriptions. •Units Conversion: Physical units conversion completely customizable. >Conversion Worksheets: •Angles: Convert angle between DEG,RAD,GRAD,DMS and Slope %. •Currencies: world currencies conversions with manual input or on-line current rates. •Interest Rates: Nominal and effective interest conversion. •Polar-Rectangular: Coordinates conversion. •Units: Physical units conversions. >General Worksheets: •Date: Calculates days between dates with Actual, 360 or 365 days calendars. •Time: Calculates time intervals between different times. •Solver: Calculates arbitrary equations entered as text expression to solve any of the variables knowing the others. •Storage Registers: Store and perform operations directly over the calculators storage registers. •Memory Content: Clear, Back-Up or Restore part or all of the Calculator's memory. •General Settings: Customize many aspects of the calculator including formats & feedbacks. •Help Documents: Description and examples of all the calculator worksheets and features. >Editors Worksheets: To create or edit data •(Date,Trx) List: Transactions and the dates they occurs for the "Account Balance Worksheet". •(Date.CF) List: Cash flows and the dates they occurs for the "Unequal Periods Cash Flows Worksheet". •(X,N) List: Cash flows and repetitions for the "Equal Periods Cash Flows Worksheet". •(X,Y) List: X and Y data samples for the Statistics worksheets. •Solver Equation: Algebraic expression for use in the "Solver" worksheet. •Units Database: Customize the "Units" worksheet. System requirements: iOS 15.0 or above. 30 days Free-Trial. In-App-Purchase: One-Payment for life. License Agreement: http://www.apple.com/legal/itunes/appstore/dev/stdeula Disclaimer: THIS IS NOT A HEWLETT PACKARD CALCULATOR, AND IS NOT SPONSORED IN ANYWAY BY HEWLETT PACKARD OR ANY OF ITS SUBSIDIARIES.

Screenshots

WP 31s1 screens
RLM4 screens

Verdict

The call

The clearest difference is in-app purchases: WP 31s at none against RLM's 4. WP 31s also leads on review sentiment (100% vs 67%) and iOS requirement (12.0 vs 15.0). RLM's advantage is update cadence (every 3 weeks vs every 10 months). On price, rating, ratings volume and ads there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. RLM sells 4 in-app purchases, starting at $0.49 per month. WP 31s asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.9 for WP 31s against 4.9 for RLM. Both are backed by a comparable volume of ratings — 15 and 7 respectively. Written reviews are what separate them: 100% of WP 31s's written reviews are positive against 67% of RLM's.

UpkeepUpdate frequency

WP 31s ships an update every 10 months, RLM every 3 weeks. The most recent releases landed on June 11, 2026 and September 10, 2026 respectively.

Scorecard5 real differences · 5 level
WP 31s versus RLM: the parameters behind the verdict, then further details
ParameterWP 31sRLM
PriceFreeFree
Rating4.9 (15 ratings)4.9 (7 ratings)
Positive reviews100.0% of reviews — better66.7% of reviews
Number of ratings15 — better7
Update frequencyEvery 10 monthsEvery 3 weeks — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS12.0 — better15.0
Further details — not scored
Size16 MB6 MB
Age rating4+4+
DeveloperPascal MeheutR.L.M. Software

Customer experience

WP 31s

All ratings15 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews11 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

RLM

All ratings7 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews3 reviews
Positive66.7%
Neutral33.3%
Negative0.0%

In-app purchases

None

WP 31s

No in-app purchases

4 purchases

RLM

Subscriptions3
  • Monthly Subscription$0.491 Month
  • Semi-Annual Subscription$2.996 Months
  • Annual Subscription$5.991 Year
One-time1
  • Lifetime Purchase$9.99

Questions

Is WP 31s free?
WP 31s is free to download, with no in-app purchases.
Is RLM free?
RLM is free to download, with in-app purchases available.
Which has better reviews, WP 31s or RLM?
WP 31s and RLM are both rated 4.9 out of 5 on the App Store, from 15 and 7 ratings respectively.
Do WP 31s or RLM have ads?
Neither WP 31s nor RLM shows ads.
Which is updated more often, WP 31s or RLM?
WP 31s ships an update every 10 months, and RLM every 3 weeks. Most recently, WP 31s was updated on June 11, 2026 and RLM on September 10, 2026.

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