# Bookshelf vs Zephyr Mobile Controller

The clearest difference is rating: Bookshelf at 4.7 against Zephyr Mobile Controller's 1.0. Bookshelf also leads on update cadence (every 6 weeks vs every 16 months) and ratings volume (78K vs 3). Zephyr Mobile Controller's advantage is iOS requirement (9.0 vs 17.6). On price, ads, in-app purchases and monetization model there is nothing between them.

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

Bookshelf holds the better App Store score, 4.7 against 1.0. That said, the two scores are not equally well evidenced: Bookshelf has 78K ratings behind it against 3, so its average is the more settled of the two. Written reviews point the same way: 22% of Bookshelf's written reviews are positive against 0% of Zephyr Mobile Controller's.

Bookshelf ships an update every 6 weeks, Zephyr Mobile Controller every 16 months. The most recent releases landed on October 16, 2026 and September 26, 2026 respectively.

## The numbers

| Metric | Bookshelf | Zephyr Mobile Controller |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (78K ratings)](https://appshunter.io/ios/app/bookshelf/id389359495/reviews)** | [1.0 (3 ratings)](https://appshunter.io/ios/app/zephyr-mobile-controller/id1447511206/reviews) |
| Number of ratings | **78K** | 3 |
| Positive reviews | **21.5% of reviews** | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 6 weeks** | Every 16 months |
| Monetization | Free | Free |
| Best chart rank | **#104** | — |
| Size | 185 MB | 73 MB |
| Requires iOS | 17.6 | **9.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [VitalSource Technologies, Inc.](https://appshunter.io/developer/333263745) | [Little Arms Studios](https://appshunter.io/developer/827625791) |

## What reviewers say

### Bookshelf

[App page](https://appshunter.io/ios/app/bookshelf/id389359495)

**Currently charting:** #104 Top Free · Education (US App Store)

Access and study your digital textbooks on your iPad or iPhone. This app allows for offline reading, note-taking, flashcard creation, and customizable reading settings. Sync your progress across devices for a seamless study experience.

**Highlights:** Offline reading, Customizable highlighters and notes, Flashcard creation, Personalized reading settings, Read Aloud feature, Cross-device syncing

**Features:** Vision Pro support

**In-app purchases:** none

**What reviewers like**

- 📚 Convenient access to textbooks
- 🔍 Useful search functionality
- 📚 Offline reading capability
- 🔖 Bookmark and note-taking features
- 🔊 Text-to-speech option

**What reviewers complain about**

- 🐛 Buggy highlighting and annotation tools
- 🖋️ Lack of Apple Pencil support
- 📚 Restricted functionality compared to other e-book apps
- 🔍 Inconsistent search and navigation experience
- 🔋 High battery consumption

**Reported bugs**

- Frequent crashes and freezes
- Issues with page loading and scrolling
- Inconsistent behavior when switching between devices
- Unreliable text-to-speech functionality

**Requested features**

- Improved highlighting and annotation tools
- Apple Pencil support for note-taking
- More customization options (e.g., font, layout, night mode)
- Seamless cross-device synchronization
- Enhanced search and navigation features


### Zephyr Mobile Controller

[App page](https://appshunter.io/ios/app/zephyr-mobile-controller/id1447511206)

Control drone simulations using your mobile device as a touchscreen controller. Connect your phone or tablet to the same network as the simulator for an immersive training experience.

**Highlights:** Touchscreen drone control, Mobile simulator interface, Network connectivity required, Requires Zephyr Drone Simulator account

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Bookshelf free?

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

### Is Zephyr Mobile Controller free?

Zephyr Mobile Controller is free to download, with no in-app purchases.

### Which has better reviews, Bookshelf or Zephyr Mobile Controller?

Bookshelf is rated higher. Bookshelf averages 4.7 out of 5 from 78K ratings, while Zephyr Mobile Controller averages 1.0 from 3 ratings.

### Do Bookshelf or Zephyr Mobile Controller have ads?

Neither Bookshelf nor Zephyr Mobile Controller shows ads.

### Which is updated more often, Bookshelf or Zephyr Mobile Controller?

Bookshelf ships an update every 6 weeks, and Zephyr Mobile Controller every 16 months. Most recently, Bookshelf was updated on October 16, 2026 and Zephyr Mobile Controller on September 26, 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.*