# Pythagoras HD vs 英作文が身につくアプリ！ BT Writing

The clearest difference is price: 英作文が身につくアプリ！ BT Writing at Free against Pythagoras HD's $0.99. 英作文が身につくアプリ！ BT Writing also leads on update cadence (every 3 months vs every 24 months). Pythagoras HD's advantage is in-app purchases (none vs 2) and iOS requirement (12.0 vs 16.6). On review sentiment, ads and device support there is nothing between them.

英作文が身につくアプリ！ BT Writing is free to download; Pythagoras HD costs $0.99 up front. 英作文が身につくアプリ！ BT Writing sells 2 in-app purchases, starting at $4.49 per month. Pythagoras HD asks for nothing beyond the download.

Pythagoras HD ships an update every 24 months, 英作文が身につくアプリ！ BT Writing every 3 months. The most recent releases landed on November 1, 2026 and November 2, 2026 respectively.

## The numbers

| Metric | Pythagoras HD | 英作文が身につくアプリ！ BT Writing |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | **[1.0 (1 ratings)](https://appshunter.io/ios/app/pythagoras-hd/id404432708/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 42.9% of reviews | **50.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 24 months | **Every 3 months** |
| Monetization | Paid | **Freemium** |
| Size | 10 MB | 26 MB |
| Requires iOS | **12.0** | 16.6 |
| Devices | iPad | **iPhone, iPad** |
| Age rating | 4+ | 4+ |
| Developer | [Roman Koksharov](https://appshunter.io/developer/700716922) | [Best Teacher, Inc.](https://appshunter.io/developer/1130896870) |

## What reviewers say

### Pythagoras HD

[App page](https://appshunter.io/ios/app/pythagoras-hd/id404432708)

Explore the Pythagorean Theorem through interactive puzzles and visual proofs. This educational app offers a unique, formula-free approach to understanding geometry. It's designed to make learning engaging and accessible.

**Highlights:** Visual proofs of Pythagorean Theorem, Interactive geometric puzzles, Formula-free learning, Engaging educational experience, iPad compatibility

**Features:** macOS Compatibility

**In-app purchases:** none


### 英作文が身につくアプリ！ BT Writing

[App page](https://appshunter.io/ios/app/bt-writing/id1438836695)

This app helps you improve your English composition skills through a five-step process, from grammar review to writing your own sentences. It offers original content created by education professionals and feedback from native speakers.

**Highlights:** Grammar confirmation, Fill-in-the-blank exercises, Sentence ordering practice, Original essay writing, Native speaker feedback, Audio playback and dictation, Progressive learning steps

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| プレミアム会員 | $4.49 | per month |
| チケット | $0.99 | one-time |


## Frequently asked questions

### Is Pythagoras HD free?

Pythagoras HD costs $0.99, with no in-app purchases.

### Is 英作文が身につくアプリ！ BT Writing free?

英作文が身につくアプリ！ BT Writing is free to download, with in-app purchases available.

### Do Pythagoras HD or 英作文が身につくアプリ！ BT Writing have ads?

Neither Pythagoras HD nor 英作文が身につくアプリ！ BT Writing shows ads.

### Which is updated more often, Pythagoras HD or 英作文が身につくアプリ！ BT Writing?

Pythagoras HD ships an update every 24 months, and 英作文が身につくアプリ！ BT Writing every 3 months. Most recently, Pythagoras HD was updated on November 1, 2026 and 英作文が身につくアプリ！ BT Writing on November 2, 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.*