# Knife Steel Composition Chart vs BookPlayer

The clearest difference is in-app purchases: Knife Steel Composition Chart at none against BookPlayer's 15. Knife Steel Composition Chart also leads on review sentiment (94% vs 83%) and iOS requirement (9.0 vs 26.0). BookPlayer's advantage is update cadence (every 9 days vs every 5 months) and ratings volume (20K vs 584). On price, rating, ads and device support there is nothing between them.

Both are free to download. BookPlayer sells 11 in-app purchases, starting at $1.99 per month. Knife Steel Composition Chart asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 4.9 for Knife Steel Composition Chart against 4.8 for BookPlayer. That said, the two scores are not equally well evidenced: BookPlayer has 20K ratings behind it against 584, so its average is the more settled of the two. Written reviews are what separate them: 94% of Knife Steel Composition Chart's written reviews are positive against 83% of BookPlayer's.

Knife Steel Composition Chart ships an update every 5 months, BookPlayer every 9 days. The most recent releases landed on October 23, 2026 and October 28, 2026 respectively.

## The numbers

| Metric | Knife Steel Composition Chart | BookPlayer |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.9 (584 ratings)](https://appshunter.io/ios/app/knife-steel-composition-chart/id498892262/reviews)** | [4.8 (20K ratings)](https://appshunter.io/ios/app/bookplayer/id1138219998/reviews) |
| Number of ratings | 584 | **20K** |
| Positive reviews | **94.3% of reviews** | 82.6% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 9 days** |
| Monetization | **Free** | Free with in-app purchases |
| Best chart rank | — | **#59** |
| Size | 4 MB | 81 MB |
| Requires iOS | **9.0** | 26.0 |
| Devices | iPhone, iPod | **iPhone, iPad, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [ZviSoft LLC](https://appshunter.io/developer/498892265) | [Gianni Carlo](https://appshunter.io/developer/1138219997) |

## What reviewers say

### Knife Steel Composition Chart

[App page](https://appshunter.io/ios/app/knife-steel-composition-chart/id498892262)

Access a comprehensive database of knife steel alloys, featuring over 6500 names and 1000 compositions. Compare alloys easily with visual bar graphs based on mass percentage, molar masses, or atomic counts. Report missing alloys or suggest improvements directly to the developer.

**Highlights:** Extensive alloy name database, Detailed composition data, Cross-reference international standards, Proprietary name equivalents, Bar graph composition comparison, Multiple comparison modes

**Features:** macOS Compatibility

**In-app purchases:** none


### BookPlayer

[App page](https://appshunter.io/ios/app/bookplayer/id1138219998)

**Currently charting:** #59 Top Free · Book, #171 Top Grossing · Book (US App Store)

This app provides a dedicated listening experience for audiobooks in M4B, M4A, MP3, and FLAC formats. It offers robust import, management, and playback features, including chapter navigation, variable playback speed, and cloud sync for seamless listening across devices.

**Highlights:** Import audiobooks via AirDrop, Files, iTunes, servers, and zip files, Manage library with progress tracking, sorting, and playlists, Advanced playback controls including speed, rewind, and volume boost, Chapter navigation and lock screen controls, Cloud sync for cross-device listening, CarPlay and Apple Watch companion app support

**Features:** macOS Compatibility, Siri integration, Apple Watch app, Vision Pro support

**In-app purchases (11)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Support Monthly (1 Month) | $1.99 | per month |
| Support Monthly (1 Month) | $2.99 | per month |
| Support Monthly (1 Month) | $3.99 | per month |
| Pro Monthly (1 Month) | $4.99 | per month |
| Support Monthly (1 Month) | $6.99 | per month |
| Support Monthly (1 Month) | $9.99 | per month |
| Pro Yearly (1 Year) | $49.99 | per year |
| Kind tip | $2.99 | one-time |
| Kind Tip | $2.99 | one-time |
| Excellent Tip | $4.99 | one-time |
| Incredible Tip | $9.99 | one-time |

**What reviewers like**

- 🚀 Flawless playback
- 👍 Intuitive and clean interface
- 💡 Ability to import from various sources
- 🚀 Fast and responsive
- 👍 Remembers playback position

**What reviewers complain about**

- 🐛 Occasional crashes or glitches
- 🐛 Issues with importing or playing certain files
- 🐛 Syncing issues between devices
- 🐛 Unreliable performance after updates

**Reported bugs**

- Playback issues with certain audio formats
- Importing problems with large audiobook libraries
- Crashes when deleting books

**Requested features**

- Bookmark management
- Percentage completion tracking
- Improved multi-file book handling
- Customizable sleep timer
- iCloud/cloud sync between devices


## Frequently asked questions

### Is Knife Steel Composition Chart free?

Knife Steel Composition Chart is free to download, with no in-app purchases.

### Is BookPlayer free?

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

### Which has better reviews, Knife Steel Composition Chart or BookPlayer?

Knife Steel Composition Chart is rated higher. Knife Steel Composition Chart averages 4.9 out of 5 from 584 ratings, while BookPlayer averages 4.8 from 20K ratings.

### Do Knife Steel Composition Chart or BookPlayer have ads?

Neither Knife Steel Composition Chart nor BookPlayer shows ads.

### Which is updated more often, Knife Steel Composition Chart or BookPlayer?

Knife Steel Composition Chart ships an update every 5 months, and BookPlayer every 9 days. Most recently, Knife Steel Composition Chart was updated on October 23, 2026 and BookPlayer on October 28, 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.*