RPN vs 1secNote
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- 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
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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
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.
- Floating note display
- AI line suggestions
- Cross-device synchronization
- Notch and status bar integration
- Retro aesthetic mode
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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
Verdict
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
RPN costs $1.99 and 1secNote $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.
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.
| Parameter | RPN | 1secNote |
|---|---|---|
| Price | $1.99 — better | $2.99 |
| Rating | 5.0 (6 ratings) — better | — |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| Number of ratings | 6 — better | — |
| Update frequency | Every 2 months | Every 4 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPod | iPhone, iPad, iPod, Mac, Apple Watch — better |
| Requires iOS | 12.0 — better | 15.0 |
| Further details — not scored | ||
| Size | 12 MB | 34 MB |
| Age rating | 4+ | 4+ |
| Developer | CuVee Software | editoy Inc. |
Customer experience
RPN
1secNote
In-app purchases
RPN
No in-app purchases
1secNote
No in-app purchases









