# Solving Pythagoras PRO vs ReadBay

The clearest difference is price: ReadBay at Free against Solving Pythagoras PRO's $1.99. ReadBay also leads on rating (4.8 vs 4.2) and update cadence (every 10 days vs every 5 weeks). Solving Pythagoras PRO's advantage is in-app purchases (none vs 4). On ads, device support and iOS requirement there is nothing between them.

ReadBay is free to download; Solving Pythagoras PRO costs $1.99 up front. ReadBay sells 4 in-app purchases, starting at $4.99 per month. Solving Pythagoras PRO asks for nothing beyond the download.

ReadBay holds the better App Store score, 4.8 against 4.2. That said, the two scores are not equally well evidenced: ReadBay has 239 ratings behind it against 35, so its average is the more settled of the two. Written reviews point the same way: 71% of Solving Pythagoras PRO's written reviews are positive against 85% of ReadBay's.

Solving Pythagoras PRO ships an update every 5 weeks, ReadBay every 10 days. The most recent releases landed on October 21, 2026 and October 23, 2026 respectively.

## The numbers

| Metric | Solving Pythagoras PRO | ReadBay |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Rating | [4.2 (35 ratings)](https://appshunter.io/ios/app/solving-pythagoras-pro/id1273601215/reviews) | **[4.8 (239 ratings)](https://appshunter.io/ios/app/readbay-book-summaries/id6499073338/reviews)** |
| Number of ratings | 35 | **239** |
| Positive reviews | 71.4% of reviews | **84.5% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 5 weeks | **Every 10 days** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 179 MB | 60 MB |
| Requires iOS | **15.0** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 17+ |
| Developer | [Glindemann, Sennoun, Langer GbR](https://appshunter.io/developer/1024972809) | [Bange Sabastine Hwonyi](https://appshunter.io/developer/1708740698) |

## What reviewers say

### Solving Pythagoras PRO

[App page](https://appshunter.io/ios/app/solving-pythagoras-pro/id1273601215)

Easily calculate the sides of a right-angled triangle using the Pythagorean theorem. Input two sides to find the third, with all calculations saved in a history. Supports fractions and provides clear solution steps.

**Highlights:** Pythagorean theorem calculations, Calculate any of the three sides, Fraction input support, Calculation history, Clear solution steps, Manual history sorting and deletion

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

**In-app purchases:** none


### ReadBay

[App page](https://appshunter.io/ios/app/readbay-book-summaries/id6499073338)

Access concise summaries and audio versions of bestselling books in under 15 minutes. Master key insights from business, self-help, and personal development titles for faster learning and habit building.

**Highlights:** 15-minute book summaries, Audiobook summaries, Offline reading, Progress tracking, Habit building challenges, Bookmark favorite notes

**Features:** macOS Compatibility

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Pro Membership | $4.99 | per month |
| Pro Annual Membership | $19.99 | per year |
| Yearly Pro Membership | $24.99 | per year |
| Lifetime Membership | $39.99 | one-time |

**What reviewers like**

- 🚀 Informative and easy to follow
- 👍 Smooth listening experience
- 👍 Broad library of titles
- 👍 Allows reading or listening
- 👍 User-friendly interface

**What reviewers complain about**

- 🐛 Usability issues when multitasking
- 🐛 Audiobook restarts from beginning
- 🔒 Lack of transparency (broken links, no contact info)
- 👎 Limited book recommendations
- 👎 Needs more book options and larger selection

**Reported bugs**

- Purchased lifetime subscription not accessible on new device
- Identical summaries for different books

**Requested features**

- Support for French books
- Ability to share summaries to Kindle
- More language options (e.g., Chinese)


## Frequently asked questions

### Is Solving Pythagoras PRO free?

Solving Pythagoras PRO costs $1.99, with no in-app purchases.

### Is ReadBay free?

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

### Which has better reviews, Solving Pythagoras PRO or ReadBay?

ReadBay is rated higher. Solving Pythagoras PRO averages 4.2 out of 5 from 35 ratings, while ReadBay averages 4.8 from 239 ratings.

### Do Solving Pythagoras PRO or ReadBay have ads?

Neither Solving Pythagoras PRO nor ReadBay shows ads.

### Which is updated more often, Solving Pythagoras PRO or ReadBay?

Solving Pythagoras PRO ships an update every 5 weeks, and ReadBay every 10 days. Most recently, Solving Pythagoras PRO was updated on October 21, 2026 and ReadBay on October 23, 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.*