Comparison

RPN vs 1secNote

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

Head to head
About

RPN

This app is a photo-realistic simulation of a classic Hewlett-Packard programmable business calculator. It offers advanced programming features, extensive register memory, and a library of pre-installed programs for various financial and statistical calculations.

Highlights
  • Photo-realistic look-and-feel
  • Programmable with subroutines and flags
  • 20 registers with unlimited store/recall
  • Indirect register addressing
  • Program library and sharing
  • Financial and statistical functions
  • Date and calendar calculations
Features
Read full description

RPN-38 CX is the first photo-realistic simulation of Hewlett-Packard's popular high-end programmable business calculator HP-38C for the iPhone. Produced from 1979 through 1983, it was the "Chive" member of the third-generation HP calculators known as the "Spice" series. While the simulator works like the original calculator, a number of carefully designed extensions make it a lot easier to use. RPN-38 CX is fully compatible with the HP-12C, except for calculations and programs involving Bonds and Depreciation. Features: • Photo-realistic look-and-feel • Programmable (99 steps, program memory not shared with register memory) • Subroutines, flags, loop control, extended conditional branching • Insert and delete steps with automatic address correction • 20 registers, "continuous", with unlimited store/recall arithmetic • Indirect register addressing • Register view • Program listing view • Program library view • Additional functions (nominal and effective interest rate) • Shortcuts for often-used key combinations • Store and retrieve any number of programs • Sharing: e-mail, AirDrop, Dropbox, copy, paste, print • 40 programs pre-installed Calculator functions: • Percentage (%, ∆%, %Total) • Simple and Compound Interest • Optional odd periods (like HP-12) • Nominal/Effective interest rate conversion • Amortization • Discounted Cash Flow Analysis • Net Present Value, Internal Rate of Return • Date and Calendar (actual or 30/360 day basis) • Statistics (mean, weighted mean, standard deviation) • Linear Regression • Additional functions not found on the HP-38: - Subroutines, flags, loop control, random number, Pi, Log, x² and more Details: cuveesoft.ch/rpn38

About

1secNote

This app allows you to view notes discreetly while using your device's camera or other applications. It offers AI-powered suggestions and syncs across all your Apple devices, with a unique retro aesthetic option.

Highlights
  • Floating note display
  • AI line suggestions
  • Cross-device synchronization
  • Notch and status bar integration
  • Retro aesthetic mode
Features
Read full description

1secNote - Floating Prompter Note Check your notes while looking at the camera. Peek at notes from the Mac's notch or menu bar. Float it over the iPhone camera app to use as a prompter. • Remote Prompter: Control the prompter using media keys (skip/play/pause) on a Bluetooth keyboard, speaker, headset, or media buttons. • Dynamic Popups: Edit directly from the notch or menu bar on Mac. Keep it floating over other apps on iPhone. • AI Suggestions: Apple Intelligence suggests the next line for you. • Full Ecosystem: Access the same notes across Mac, iPhone, iPad, and Apple Watch. • Private & Sync: Securely backed up to your personal iCloud and synced in real-time. • Retro Aesthetic: Decorate your screen with classic pixel fonts in vintage pixel art mode.

Screenshots

RPN4 screens
1secNote4 screens

Verdict

The call

The clearest difference is update cadence: 1secNote at every 4 weeks against RPN's every 2 months. 1secNote also leads on device support (5 vs 2). RPN's advantage is price ($1.99 vs $2.99) and iOS requirement (12.0 vs 15.0). On review sentiment, ads, in-app purchases and monetization model 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

RPN costs $1.99 and 1secNote $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

RPN ships an update every 2 months, 1secNote every 4 weeks. The most recent releases landed on October 12, 2026 and October 7, 2026 respectively.

Scorecard4 real differences · 6 level
RPN versus 1secNote: the parameters behind the verdict, then further details
ParameterRPN1secNote
Price$1.99 — better$2.99
Rating5.0 (6 ratings) — better—
Positive reviews100.0% of reviews100.0% of reviews
Number of ratings6 — better—
Update frequencyEvery 2 monthsEvery 4 weeks — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPodiPhone, iPad, iPod, Mac, Apple Watch — better
Requires iOS12.0 — better15.0
Further details — not scored
Size12 MB34 MB
Age rating4+4+
DeveloperCuVee Softwareeditoy Inc.

Customer experience

RPN

All ratings6 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews4 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

1secNote

Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

RPN

No in-app purchases

None

1secNote

No in-app purchases

Questions

Is RPN free?
RPN costs $1.99, with no in-app purchases.
Is 1secNote free?
1secNote costs $2.99, with no in-app purchases.
Do RPN or 1secNote have ads?
Neither RPN nor 1secNote shows ads.
Which is updated more often, RPN or 1secNote?
RPN ships an update every 2 months, and 1secNote every 4 weeks. Most recently, RPN was updated on October 12, 2026 and 1secNote on October 7, 2026.

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