# RLM vs DB40X

The clearest difference is rating: DB40X at 4.7 against RLM's 4.1. DB40X also leads on in-app purchases (none vs 4). RLM's advantage is review sentiment (80% vs 67%). On price, ratings volume, update cadence and ads there is nothing between them.

Both are free to download. RLM sells 4 in-app purchases, starting at $0.49 per month. DB40X asks for nothing beyond the download.

DB40X holds the better App Store score, 4.7 against 4.1. Both are backed by a comparable volume of ratings — 17 and 7 respectively. Written reviews complicate that: 80% of RLM's written reviews are positive against 67% of DB40X's, so the app with the better star average is not the one people write more warmly about.

RLM ships an update monthly, DB40X every 3 weeks. The most recent releases landed on September 10, 2026 and June 4, 2026 respectively.

## The numbers

| Metric | RLM | DB40X |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.1 (17 ratings)](https://appshunter.io/ios/app/rlm-15cx/id1636646608/reviews) | **[4.7 (7 ratings)](https://appshunter.io/ios/app/db40x/id6624315901/reviews)** |
| Number of ratings | **17** | 7 |
| Positive reviews | **80.0% of reviews** | 66.7% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Monthly | **Every 3 weeks** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 6 MB | 7 MB |
| Requires iOS | 15.0 | **14.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [R.L.M. Software](https://appshunter.io/developer/289639238) | [Christophe de Dinechin](https://appshunter.io/developer/1761608161) |

## What reviewers say

### RLM

[App page](https://appshunter.io/ios/app/rlm-15cx/id1636646608)

This advanced scientific calculator emulates the functionality of the HP-15C, offering comprehensive tools for finance, business, statistics, and scientific calculations. It supports programming, equation solving, and unit conversions, optimized for iOS devices.

**Highlights:** Programmable advanced scientific calculator, Finance and business calculation menus, Statistics and probability functions, Complex numbers and matrix operations, Unit and currency conversions, Equation solver and programming capabilities

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Subscription | $0.49 | per month |
| Semi-Annual Subscription | $2.99 | per 6 months |
| Annual Subscription | $5.99 | per year |
| One-Time Purchase | $9.99 | one-time |


### DB40X

[App page](https://appshunter.io/ios/app/db40x/id6624315901)

A high-precision scientific calculator inspired by the HP48 series, offering arbitrary precision computations, complex numbers, vectors, matrices, and graphing. It supports RPN and algebraic operations, with over 1000 built-in functions and a hyperlinked help system.

**Highlights:** Arbitrary precision computations, RPN and algebraic operations, Complex numbers, vectors, and matrices, Graphing and plotting, Engineering units and conversions, Hyperlinked help system

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is RLM free?

RLM is free to download, with in-app purchases available.

### Is DB40X free?

DB40X is free to download, with no in-app purchases.

### Which has better reviews, RLM or DB40X?

DB40X is rated higher. RLM averages 4.1 out of 5 from 17 ratings, while DB40X averages 4.7 from 7 ratings.

### Do RLM or DB40X have ads?

Neither RLM nor DB40X shows ads.

### Which is updated more often, RLM or DB40X?

RLM ships an update monthly, and DB40X every 3 weeks. Most recently, RLM was updated on September 10, 2026 and DB40X on June 4, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*