HP 15c Calculator vs Smart Adding Machine
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
HP 15c Calculator
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 emulator
- RPN (Reverse Polish Notation)
- Matrix calculations
- Complex functions
- Numerical integration
- Programmable (448 lines)
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Meet the next generation of your favorite scientific calculator. The official HP 15c app, now brings a completely redesigned interface, a modern look, and improved functionality—while preserving the precision and reliability trusted by professionals for decades. This RPN calculator offers the features, algorithms and calculation sequences of the original 15c Scientific Calculator conveniently stored on your iPhone or iPad. The HP 15c You Know – Now Better Than Ever • Official emulator of legendary calculator device by HP • Identical algorithms, layout, and keystrokes as the original HP 15c • RPN (Reverse Polish Notation) for fast and efficient input • Matrix calculations, Complex functions, Numerical integration. • Ideal for math and engineering students and professionals • Programmable – up to 448 lines Be Ready. Anywhere. Anytime. Whether you’re in class, at the office, or on the go, HP 15c is ready when you are. Just launch the app on your iPhone and get to work. Download HP 15c today and experience the perfect blend of classic functionality and modern design.
Smart Adding Machine
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This app has a numeric keyboard. It may not always be visible. If it is not visible, pressing the input button that has the text 'Insert an Amount or ...', will cause one to appear. If you want to hide it, select the button on the left titled 'Hide KB'. The Adding Machine contains a visual tape with two columns of numbers. The left is the amount you keyed. The right column has in a '1' which is the count. The system puts in a '1' for you. As you add items, the tape grows. The last item is always followed by an empty item colored red. This color red is important because it indicates where your next entry will be placed!!! After entering a number, press the 'Save' button. If this is your first entry, two items will appear on the tape. The first one will contain the number you keyed. The second will be red with the amount showing: 0.00 and a count showing 1. This pattern will continue as you add items On the left side of the screen are 11 buttons in a column. The first six are for moving the red color - but not its contents. This allows for the correction of errors. The first two are: first - go to tape start & second to tape end (red item). The second two go up one item and down one item on the tape. The last of the group switch between amount & count - usually used to change the count from 1. There a 4 named buttons the effect the tape: Clear, Insert (an empty row where the red is, Delete(the row that a red item) and Hide KB. The keyboard has no minus sign. There is a slider button that can be used to cause an number to be negative. It is red for emphasis At least 50 items can be entered. The tape can be scrolled by using your finger to see the entire tape. At the very top of the screen is a 'Help' chevron that switches to a page of help text.
Screenshots
Verdict
The clearest difference is price: Smart Adding Machine at $3.99 against HP 15c Calculator's $14.99. Smart Adding Machine also leads on update cadence (every 3 weeks vs every 16 months). HP 15c Calculator's advantage is iOS requirement (15.6 vs 17.0). On ads, in-app purchases and device support 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
HP 15c Calculator costs $14.99 and Smart Adding Machine $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.
HP 15c Calculator ships an update every 16 months, Smart Adding Machine every 3 weeks. The most recent releases landed on September 28, 2026 and September 9, 2026 respectively.
| Parameter | HP 15c Calculator | Smart Adding Machine |
|---|---|---|
| Price | $14.99 | $3.99 — better |
| Rating | 4.8 (207 ratings) — better | — |
| Positive reviews | 68.0% of reviews | — |
| Number of ratings | 207 — better | — |
| Update frequency | Every 16 months | Every 3 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | — |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Mac |
| Requires iOS | 15.6 — better | 17.0 |
| Further details — not scored | ||
| Size | 45 MB | 0 MB |
| Age rating | 4+ | 4+ |
| Developer | MORAVIA Consulting, spol. s r.o. | Harry Detrick |
Bugs and requests
HP 15c Calculator
Reported bugs
3 issues- Numbers not aligned in display window
- Display flashing after running programs
- Incompatibility with latest iOS versions
Requested features
4 requests- Copy and paste functionality
- Ability to change calculator models
- Option to disable button click sound
- Better support for larger iPhone screens
Smart Adding Machine
Not enough reviews yet to summarise bugs or requests.
In-app purchases
HP 15c Calculator
No in-app purchases
Smart Adding Machine
No in-app purchases
Questions
Is HP 15c Calculator free?
Is Smart Adding Machine free?
Do HP 15c Calculator or Smart Adding Machine have ads?
Which is updated more often, HP 15c Calculator or Smart Adding Machine?
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