LeftRightDiary vs Book Isle
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
LeftRightDiary
This app allows you to record life's moments using text and images, with support for Markdown editing. It prioritizes privacy by storing all data locally on your device and offers various ways to review past entries.
- Markdown and Rich Text editing
- Mixed text and image layout
- Heatmap and Calendar views
- Random memory recall
- Local data storage
- WebDAV and Alibaba Cloud Disk sync
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**Capture Every Moment** With Zuoyou Diary, record every moment of your life! 【Product Introduction】 Zuoyou Diary is a simple and pure diary app! It supports writing journals in Markdown, combining text and images. All basic features are completely free. All diary data is stored only on your device — your privacy is our top priority, so you never have to worry about data leaks. In addition, you can easily review past entries through various views such as Heatmap, Calendar, Random Recall, and "On This Day in the Past." Everything is clearly laid out so you can effortlessly keep track of life's little moments. 【Key Features】 * Supports both Markdown and Rich Text editors * Mixed text and image layout * Heatmap support * Calendar view (with heatmap) * Calendar image view * On this day in the past * Random memory recall * Privacy-focused: data stored locally on your device * Sync via WebDAV * Sync with Alibaba Cloud Disk
Book Isle
This app allows you to connect to your personal NAS, WebDAV, SMB, OPDS, or Calibre library to import, browse, search, download, and read local and remote books. It supports a wide range of file formats and offers a robust local reading experience with features like full-text search and highlighting.
- Connect to NAS, WebDAV, SMB, OPDS, Calibre
- Import and manage multiple book formats
- Full-text search and bookmarking
- Remote reading and downloading
- Private synchronization of reading progress
- Face ID app lock for privacy
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Book Isle is an e-book reader designed for personal private libraries. You can connect your iPhone and iPad to your own NAS, WebDAV, SMB, OPDS, or Calibre library, import, browse, search, download, and read local and remote books. The app does not provide an online bookstore, does not host or distribute book content, and your book files are still managed by your local device or your own private library. Main functions: - Private library connection: Supports WebDAV, SMB, OPDS, Calibre Content Server, and Calibre metadata.db. - Multi-format bookshelf: Supports the import, management, and reading of TXT, EPUB, PDF, Markdown, HTML, FB2, RTF, DOCX, CBZ, and common audiobook formats; MOBI, AZW, AZW3, CBR, DJVU can be imported, managed, filtered, and synchronized. It is recommended to convert them to EPUB, PDF, or CBZ for reading. - Local reading experience: Supports bookshelf grid/list, sorting, tagging, rating, reading status, full-text search, bookmarking, notes, highlighting, book excerpt cards, and reading statistics. - Remote reading and downloading: Browse private libraries from NAS, OPDS, or Calibre, download or stream supported book formats on demand. - Private synchronization: Synchronize reading progress, book metadata, notes, highlights, tags, reading statistics, and reading settings through the WebDAV directory you have configured. - Privacy and security: No self-built account system; supports Face ID app lock; book files will not be automatically uploaded to our servers due to synchronization function. ShuYu is suitable for readers who already have NAS, Calibre, WebDAV directories, or OPDS book sources, allowing them to manage their private book collections with a quiet and reliable reader. Subscription and purchase instructions: Bibliophile Pro offers monthly and annual memberships with automatic renewal, as well as a one-time purchase for a permanent membership. After activation, users can enjoy member-only features such as browsing, searching, downloading, and remote reading of private libraries via NAS/WebDAV/SMB, OPDS, Calibre, as well as private WebDAV synchronization. Monthly and annual memberships are auto-renewable subscriptions on the App Store. After confirming your purchase, the fee will be deducted from your Apple ID account; the subscription will automatically renew before the end of the current period, unless you turn off auto-renewal at least 24 hours before the end of the current subscription period; the renewal fee will be confirmed and deducted by Apple within 24 hours before the end of the current period. You can manage or cancel your subscription in iOS Settings > Apple ID > Subscriptions, or open the App Store subscription management page from the in-app membership page. After canceling your subscription, you can still use the membership benefits until the end of the current paid period. The actual price, trial, promotions, and available items are subject to the display on the App Store purchase confirmation page. Refunds are processed by Apple according to its rules. After membership expires, is cancelled, is refunded, or the transaction is revoked, the remote library and private sync features that require membership will be locked; downloaded books, local reading, local notes, and local shelf management can still be used. The specific agreement is as follows: Terms: https://sobison.github.io/nasbook/auto-renewable-subscription-terms.html membership: https://sobison.github.io/nasbook/membership-agreement.html Privacy: https://sobison.github.io/nasbook/privacy-policy.html
Screenshots
Verdict
The clearest difference is price: LeftRightDiary at Free against Book Isle's $0.99. Book Isle's advantage is review sentiment (89% vs 50%) and update cadence (weekly vs monthly). On rating, ratings volume, ads and in-app purchases there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
LeftRightDiary is free to download; Book Isle costs $0.99 up front. LeftRightDiary sells 3 one-off in-app purchases and Book Isle sells 3 in-app purchases, starting at $0.99 per month. Whichever you choose, the download price is not the number that matters.
On the App Store both sit at effectively the same score — 5.0 for LeftRightDiary against 5.0 for Book Isle. Both are backed by a comparable volume of ratings — 1 and 2 respectively. Written reviews are what separate them: 50% of LeftRightDiary's written reviews are positive against 89% of Book Isle's.
LeftRightDiary ships an update monthly, Book Isle weekly. Both last shipped on October 24, 2026.
| Parameter | LeftRightDiary | Book Isle |
|---|---|---|
| Price | Free — better | $0.99 |
| Rating | 5.0 (1 ratings) | 5.0 (2 ratings) |
| Positive reviews | 50.0% of reviews | 89.2% of reviews — better |
| Number of ratings | 1 | 2 — better |
| Update frequency | Monthly | Weekly — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.0 — better | 15.6 |
| Further details — not scored | ||
| Size | 80 MB | 50 MB |
| Age rating | 4+ | 9+ |
| Developer | 候军 袁 | Anyi County Bingzhiyi Trading Co., Ltd. |
Customer experience
LeftRightDiary
Book Isle
In-app purchases
LeftRightDiary
- Upgrade to PRO$3.99
- 请作者吃大餐$9.99
- 大力支持$29.99
Book Isle
- Monthly membership$0.991 Month
- Annual Membership$2.991 Year
- Permanent member$7.99









