# RxMarbles vs Kanji Trainer

The clearest difference is in-app purchases: RxMarbles at none against Kanji Trainer's 1. RxMarbles also leads on ratings volume (16 vs 2) and iOS requirement (9.2 vs 13.0). On price, rating, update cadence and ads there is nothing between them.

Both are free to download. Kanji Trainer sells 1 in-app purchase, starting at $9.99 per year. RxMarbles asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 4.9 for RxMarbles against 5.0 for Kanji Trainer. That said, the two scores are not equally well evidenced: RxMarbles has 16 ratings behind it against 2, so its average is the more settled of the two.

RxMarbles ships an update every 4 months, Kanji Trainer every 3 months. The most recent releases landed on November 2, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | RxMarbles | Kanji Trainer |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.9 (16 ratings)](https://appshunter.io/ios/app/rxmarbles/id1087272442/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/kanji-trainer/id1619482195/reviews)** |
| Number of ratings | **16** | 2 |
| Positive reviews | 86.2% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 3 months** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 21 MB | 20 MB |
| Requires iOS | **9.2** | 13.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [AnjLab](https://appshunter.io/developer/501327862) | [Ulrich Neymeyr](https://appshunter.io/developer/1619482197) |

## What reviewers say

### RxMarbles

[App page](https://appshunter.io/ios/app/rxmarbles/id1087272442)

Visualize and understand ReactiveX observable sequences with interactive diagrams. This educational tool helps developers grasp complex asynchronous programming concepts by illustrating event-based data streams and composition operators.

**Highlights:** Interactive observable diagrams, Visualization of event streams, Demonstration of composition operators, Educational tool for asynchronous programming, Explains observer pattern extensions

**Features:** macOS Compatibility

**In-app purchases:** none


### Kanji Trainer

[App page](https://appshunter.io/ios/app/kanji-trainer/id1619482195)

Master Japanese kanji with mnemonic phrases derived from etymological backgrounds. This app offers targeted repetition, detailed statistics, and training modes for reading, writing, and radicals. Learn 2136 Joyo-Kanji and 500 radicals effectively.

**Highlights:** Mnemonic phrases based on etymology, Reading and writing practice, Targeted repetition of unlearned characters, Detailed learning statistics, 2136 Joyo-Kanji included, Radical training modes

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium | $9.99 | per year |


## Frequently asked questions

### Is RxMarbles free?

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

### Is Kanji Trainer free?

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

### Which has better reviews, RxMarbles or Kanji Trainer?

Kanji Trainer is rated higher. RxMarbles averages 4.9 out of 5 from 16 ratings, while Kanji Trainer averages 5.0 from 2 ratings.

### Do RxMarbles or Kanji Trainer have ads?

Neither RxMarbles nor Kanji Trainer shows ads.

### Which is updated more often, RxMarbles or Kanji Trainer?

RxMarbles ships an update every 4 months, and Kanji Trainer every 3 months. Most recently, RxMarbles was updated on November 2, 2026 and Kanji Trainer on November 3, 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.*