# K2Sonnet vs Pythagorus doodlus

The clearest difference is in-app purchases: K2Sonnet at none against Pythagorus doodlus's 1. K2Sonnet also leads on ads (none vs shown). Pythagorus doodlus's advantage is update cadence (every 6 days vs every 7 months). On price, device support and iOS requirement there is nothing between them.

Both are free to download. Pythagorus doodlus sells 1 in-app purchase, starting at $4.99 per year. K2Sonnet asks for nothing beyond the download.

K2Sonnet ships an update every 7 months, Pythagorus doodlus every 6 days. The most recent releases landed on October 24, 2026 and October 15, 2026 respectively.

## The numbers

| Metric | K2Sonnet | Pythagorus doodlus |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[1.0 (1 ratings)](https://appshunter.io/ios/app/k2sonnet/id6753734747/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 7 months | **Every 6 days** |
| Size | 2 MB | 7 MB |
| Requires iOS | 17.6 | 17.6 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 17+ | 4+ |
| Developer | [Shanghai Jiyue Information Technology Co., Ltd.](https://appshunter.io/developer/1795192424) | [Stéphan Barbé](https://appshunter.io/developer/313949257) |

## What reviewers say

### K2Sonnet

[App page](https://appshunter.io/ios/app/k2sonnet/id6753734747)

**Features:** macOS Compatibility

**In-app purchases:** none


### Pythagorus doodlus

[App page](https://appshunter.io/ios/app/pythagorus-doodlus/id6754364531)

**Features:** macOS Compatibility, Family Sharing

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium | $4.99 | per year |


## Frequently asked questions

### Is K2Sonnet free?

K2Sonnet is free to download, with no in-app purchases.

### Is Pythagorus doodlus free?

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

### Do K2Sonnet or Pythagorus doodlus have ads?

Pythagorus doodlus shows ads; K2Sonnet does not.

### Which is updated more often, K2Sonnet or Pythagorus doodlus?

K2Sonnet ships an update every 7 months, and Pythagorus doodlus every 6 days. Most recently, K2Sonnet was updated on October 24, 2026 and Pythagorus doodlus on October 15, 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.*