Interchange vs Emma’s Library
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Interchange
Convert and read a wide variety of ebook formats, including DRM-protected files. Offers extensive customization for reading, note-taking, and book management. Supports multiple import methods and file decompression.
- Multiple ebook format conversion
- DRM removal for Kindle books
- Customizable ebook reader layout
- Note-taking and bookmarking
- Customizable book covers
- Multiple page-turning methods
- Comic reading support
- Advanced book management
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Functional Features 1. Supports multiple format conversions: txt, epub, mobi, azw, azw3, prc, pdf, markdown, docx, htmlz, fb2, etc. For txt files, automatically extract chapter directories. 2. Support removing DRM protected book files (Kindle DRM). 3. A comprehensive e-book reader that supports multiple formats: txt epub、mobi、azw、azw3、prc、pdf。 Powerful custom layout layout, including line spacing, paragraph spacing, first line indentation, top and bottom spacing, left and right spacing, custom background, custom font, global progress drag, and global search. Rich note taking and bookmarking functions. 4. Support custom book covers, online search, and album selection, even txt can have beautiful covers. Simultaneously editable, cropped, and filtered. 5. Provide multiple page turning methods, including overlay, translation, simulation, scrolling, automatic scrolling reading, landscape reading, and dual column reading. 6. Supports comic reading, with maximum screen ratio and maximum clarity for reading comics. Support scrolling mode for reading comics. 7. Powerful book management function, supporting grouping, renaming, sorting, dragging and merging groups, batch deletion, and moving operations. 8. Support modifying book element data such as title, author, ASIN, ISBN, time, publisher, etc. 9. Multiple file transfer methods, importing book files through WiFi, computer, Baidu cloud storage, local devices, and other application sharing methods for convenience and ease. 10. Quickly decompress compressed files such as zip, rar, 7z, etc. 11. Password protection function, can set gesture password, facial recognition unlock. 12. There are more features waiting for you to explore. [Automatic Subscription Instructions] --Subscription period: 1 month --Price: ¥ 18 --Subscription auto renewal, unless auto renewal is closed at least 24 hours before the end of the current term. --Payment will be charged to iTunes account upon confirmation of purchase --The account will receive renewal fees within 24 hours before the end of the current period, and the renewal fees will be determined --Subscription can be managed by users themselves, and automatic subscription can be disabled by entering their personal account on the App Store after purchase --If any unused portion of the free trial period is provided, it will be forfeited upon the user's purchase of the publication's subscription (if applicable) --Subscription period: 1 year --Price: ¥ 30 --Subscription auto renewal, unless auto renewal is closed at least 24 hours before the end of the current term --Payment will be charged to iTunes account upon confirmation of purchase --The account will receive renewal fees within 24 hours before the end of the current period, and the renewal fees will be determined --Subscription can be managed by users themselves, and automatic subscription can be disabled by entering their personal account on the App Store after purchase --If any unused portion of the free trial period is provided, it will be forfeited upon the user's purchase of the publication's subscription (if applicable) --Service Terms: http://blog.sina.com.cn/s/blog_a02518890102xuoh.html --Privacy Policy: http://blog.sina.com.cn/s/blog_a02518890102xtq4.html
Emma’s Library
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Finish every listen with something useful. Emma’s Library brings together audiobooks across science, history, biographies, business, nature, and big ideas—plus read-along text and quick quizzes that help you notice what stayed. Start with free listening, then choose Emma Premium for access to the complete Premium collection and protected offline downloads. LISTEN YOUR WAY • Stream audiobooks with background and Lock Screen controls • Follow chapters and transcript-aligned read-along • Adjust playback speed, queue what is next, and set a sleep timer • Download eligible books for listening without a connection TURN LISTENING INTO LEARNING • Take quick quizzes and practise Battle of the Books recall • Build a private learning passport from completed listening and quiz evidence • See listening insights, streaks, achievements, and recommendations READ TOGETHER • Save and share personal playlists • Create reading groups for family, friends, or book clubs • Set finish-together dates and follow each reader’s progress Grown-ups is the default experience. A Kids profile is available as an optional filtered view; Emma’s Library is not listed in the Kids category. No account is required to start listening. Emma creates a private profile for this device automatically. Link it later with Apple, Google, or a passwordless email code to recover your library, sync across devices, use Reading Groups, or get Premium. Emma Premium is available as monthly and annual auto-renewing subscriptions. Payment is charged to your Apple Account. Subscriptions renew unless cancelled at least 24 hours before the current period ends. Manage or cancel in your Apple Account subscription settings. Prices and periods shown by the App Store control. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Screenshots
Verdict
The clearest difference is iOS requirement: Interchange at 12.2 against Emma’s Library's 17.0. On price, update cadence, 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
Both are free to download. Interchange sells 9 in-app purchases, starting at $2.49 per month and Emma’s Library sells 2 in-app purchases, starting at $5.99 per month. Whichever you choose, the download price is not the number that matters.
Interchange ships an update every 6 days, Emma’s Library weekly. The most recent releases landed on November 2, 2026 and October 31, 2026 respectively.
| Parameter | Interchange | Emma’s Library |
|---|---|---|
| Price | Free | Free |
| Rating | 4.3 (212 ratings) — better | — |
| Positive reviews | 73.2% of reviews | — |
| Number of ratings | 212 — better | — |
| Update frequency | Every 6 days — better | Weekly |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Subscription | — |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 12.2 — better | 17.0 |
| Further details — not scored | ||
| Size | 103 MB | 8 MB |
| Age rating | 17+ | 12+ |
| Developer | 小龙 刘 | Qia Li |
Bugs and requests
Interchange
Reported bugs
11 issues- App crashes when changing covers
- Ad close buttons are too small or non-functional
- Converted files show as 0 bytes
- App crashes when deleting empty files
- Pro version features still require upgrade prompts
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- Converted PDFs have missing images and jumbled text
- Files vanish after sending to Kindle
- Conversion fails despite payment
- App shows ads instead of converting files
- Cover metadata not preserved in conversions
- Right-to-left text displays incorrectly
Requested features
8 requests- Batch conversion capability
- Right-to-left text support for Arabic books
- Proper cover image inclusion in conversions
- Unlimited conversions
- iPad Pro landscape orientation support
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- Ability to send files to Kindle over WiFi
- Bookmark synchronization across devices
- Better ad implementation with working close buttons
Emma’s Library
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Interchange
- UNLOCK ALL FEATURES, REMOVE AD$2.491 Month
- UNLOCK ALL FEATURES, REMOVE AD$4.991 Year
- REMOVE ALL ADS$1.99
- Conversions+50$1.99
- All formats2 variants$1.99
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- Conversions+600$2.99
- Conversions+1000$3.99
- ALL ACCESS, REMOVING AD$9.99
- All advanced features$9.99
Emma’s Library
- Emma Premium Monthly$5.991 Month
- Emma Premium Annual$59.991 Year









