# one digit addition vs Sosu der

The clearest difference is ads: one digit addition at none against Sosu der's shown. one digit addition also leads on iOS requirement (8.0 vs 15.0). Sosu der's advantage is update cadence (every 4 months vs every 13 months). On price, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

one digit addition ships an update every 13 months, Sosu der every 4 months. The most recent releases landed on October 23, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | one digit addition | Sosu der |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.0 (1 ratings)](https://appshunter.io/ios/app/one-digit-addition/id424279638/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | Every 13 months | **Every 4 months** |
| Monetization | Free | — |
| Size | 4 MB | 140 MB |
| Requires iOS | **8.0** | 15.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Currach Software](https://appshunter.io/developer/315759561) | [Hirobumi Onishi](https://appshunter.io/developer/1740115066) |

## What reviewers say

### one digit addition

[App page](https://appshunter.io/ios/app/one-digit-addition/id424279638)

Practice single-digit addition with this game. It features nine stages with random questions, offering a speed puzzle and search game experience. This is a lite version of a more comprehensive math app.

**Highlights:** Single-digit addition practice, Speed puzzle game, Search game mode, Nine stages with random questions, Lite version of a full math app

**Features:** macOS Compatibility

**In-app purchases:** none


### Sosu der

[App page](https://appshunter.io/ios/app/sosu-der/id6483364985)

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

**In-app purchases:** none


## Frequently asked questions

### Is one digit addition free?

one digit addition is free to download, with no in-app purchases.

### Is Sosu der free?

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

### Do one digit addition or Sosu der have ads?

Sosu der shows ads; one digit addition does not.

### Which is updated more often, one digit addition or Sosu der?

one digit addition ships an update every 13 months, and Sosu der every 4 months. Most recently, one digit addition was updated on October 23, 2026 and Sosu der on October 25, 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.*