Gadgifyr Apps
July 8, 2026
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9 min
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Read More, Forget Less: 5 Apps Built for Retention, Not Just Bookmarks
Most people who want to read more already have an app on their phone — the harder part is building the habit and retaining what they read. This blog compares five reading apps on the features that actually matter for long-term reading: annotation tools, format support, and the mechanics that help a habit stick.
Why Reading Apps Are Not All Doing the Same Job
For most people, the barrier to reading more is not a shortage of books — it is consistency. Starting a book is easy; finishing it and actually remembering what was in it is harder. Reading apps vary considerably in how much they help with that second part. Some are built primarily as storefronts with a reader attached. Others are highly customisable tools designed around the experience of the person reading. And a few occupy the middle ground, offering a catalogue and just enough structure to keep a reading habit moving forward.
The five apps here — Kindle, Audible, Libby, Scribd, and Moon+ Reader — cover that full spectrum: from Amazon’s deeply integrated ebook and audiobook ecosystem, to a completely free library borrowing app, to a technically advanced Android reader for users who bring their own files. Understanding what each one is actually built around — and where its design choices support or undermine a reading habit — is the most practical way to choose.
Kindle
A digital reading ecosystem designed to make books accessible anywhere and on almost any device.
The Kindle app is Amazon’s ebook reading platform, available on iOS, Android, and desktop, giving users access to their Amazon ebook purchases alongside their Kindle library. It offers full cross-device sync via Whispersync, meaning reading progress, highlights, and notes follow the reader across every device on the same account. The app includes a daily reading goal tracker, vocabulary builder, reading streaks, and the ability to pair ebooks with Audible audiobooks for Immersive Reading — a mode that highlights text in real time as the audiobook narration plays.
Kindle’s strongest quality is its annotation and retention ecosystem. Highlights are stored, synced, and accessible across all devices; they can be reviewed in a dedicated highlights view and exported for use in note-taking apps. The vocabulary builder turns words the reader has looked up into a reviewable flashcard list. Daily reading goals and streaks add a light habit-forming layer, and the Immersive Reading mode is particularly effective for readers who lose focus when reading text alone — engaging both visual and auditory attention simultaneously.
The primary limitation is that Kindle is an Amazon-closed ecosystem. Users can only read content purchased through or compatible with Amazon — DRM-protected files from other stores will not open in the app. Kindle Unlimited adds a borrowing layer for an additional monthly fee, but for readers with existing ebook libraries in other formats, Moon+ Reader is the more versatile choice. Compared to Libby, Kindle carries an ongoing cost; compared to Scribd, it does not bundle audiobooks by default.
Best suited for readers who purchase ebooks regularly and want the most complete annotation, retention, and cross-format reading experience available in a single app.
Kindle’s strongest quality is its annotation and retention ecosystem. Highlights are stored, synced, and accessible across all devices; they can be reviewed in a dedicated highlights view and exported for use in note-taking apps. The vocabulary builder turns words the reader has looked up into a reviewable flashcard list. Daily reading goals and streaks add a light habit-forming layer, and the Immersive Reading mode is particularly effective for readers who lose focus when reading text alone — engaging both visual and auditory attention simultaneously.
The primary limitation is that Kindle is an Amazon-closed ecosystem. Users can only read content purchased through or compatible with Amazon — DRM-protected files from other stores will not open in the app. Kindle Unlimited adds a borrowing layer for an additional monthly fee, but for readers with existing ebook libraries in other formats, Moon+ Reader is the more versatile choice. Compared to Libby, Kindle carries an ongoing cost; compared to Scribd, it does not bundle audiobooks by default.
Best suited for readers who purchase ebooks regularly and want the most complete annotation, retention, and cross-format reading experience available in a single app.
Retention Improvement With Gamified Reading Tools
Research into reading engagement has found that gamified reading tools — those using streaks, goals, and progress tracking — can improve retention by up to 75% compared to unstructured reading. This finding points to something practical: the habit-supporting design of an app, not just its library size, is a meaningful factor in whether a reader actually finishes books and remembers what they read.
75%
U.S. Audiobook Market Revenue in 2024
According to data from the Association of American Publishers, the U.S. audiobook market reached $1.1 billion in revenue in 2024, growing by nearly 24% year-over-year. This rapid growth reflects a broader shift in how people consume books — with listening during commutes, exercise, and household tasks becoming a primary reading format for a growing share of adults.
$1.1B
U.S. Adults Who Read at Least One Book Last Year
Pew Research Center data from October 2025 found that 64% of U.S. adults read at least one book in the past year in any format. While this number has remained broadly stable, research consistently shows that the gap is not in access to books but in maintaining the habit of finishing them — which is where the design choices in reading apps make a real practical difference.
64%
How People Are Reading — and What Helps It Stick
Audible is Amazon’s dedicated audiobook platform, offering one of the largest catalogues of professionally narrated audiobooks available anywhere. It operates on a credit-based subscription model: users receive one or more credits per month that can be exchanged for any title, and purchased audiobooks are owned permanently. The app supports variable playback speed, bookmarks, chapter navigation, a sleep timer, and a Read & Listen mode that syncs audiobook narration with Kindle ebook text in real time for compatible paired titles.
Audible’s most significant advantage is its catalogue size and content ownership model. With the credit system, titles are purchased rather than rented — they remain accessible even after a subscription ends. The catalogue covers more premium and new-release audiobook titles than Scribd, and narration quality across major publishers is consistently high. For readers who primarily consume books by listening during commutes or exercise, Audible is the most reliable format-specific platform in this comparison.
The trade-off is that Audible does not support ebook reading independently — it requires pairing with Kindle for that. Users who want both formats from one subscription will find Scribd a more economical option. Audible’s annotations are limited to bookmarks and short notes on specific timestamps, which are less useful for retention than the structured highlight and note systems in Kindle and Moon+ Reader. Compared to Libby, it carries a cost; compared to Scribd, it offers permanent ownership and a larger premium catalogue.
Best suited for regular audiobook listeners who want permanent ownership of titles, high narration quality, and access to the widest range of new releases.
Audible’s most significant advantage is its catalogue size and content ownership model. With the credit system, titles are purchased rather than rented — they remain accessible even after a subscription ends. The catalogue covers more premium and new-release audiobook titles than Scribd, and narration quality across major publishers is consistently high. For readers who primarily consume books by listening during commutes or exercise, Audible is the most reliable format-specific platform in this comparison.
The trade-off is that Audible does not support ebook reading independently — it requires pairing with Kindle for that. Users who want both formats from one subscription will find Scribd a more economical option. Audible’s annotations are limited to bookmarks and short notes on specific timestamps, which are less useful for retention than the structured highlight and note systems in Kindle and Moon+ Reader. Compared to Libby, it carries a cost; compared to Scribd, it offers permanent ownership and a larger premium catalogue.
Best suited for regular audiobook listeners who want permanent ownership of titles, high narration quality, and access to the widest range of new releases.
Retention Improvement With Gamified Reading Tools
Research into reading engagement has found that gamified reading tools — those using streaks, goals, and progress tracking — can improve retention by up to 75% compared to unstructured reading. This finding points to something practical: the habit-supporting design of an app, not just its library size, is a meaningful factor in whether a reader actually finishes books and remembers what they read.
75%
U.S. Audiobook Market Revenue in 2024
According to data from the Association of American Publishers, the U.S. audiobook market reached $1.1 billion in revenue in 2024, growing by nearly 24% year-over-year. This rapid growth reflects a broader shift in how people consume books — with listening during commutes, exercise, and household tasks becoming a primary reading format for a growing share of adults.
$1.1B
U.S. Adults Who Read at Least One Book Last Year
Pew Research Center data from October 2025 found that 64% of U.S. adults read at least one book in the past year in any format. While this number has remained broadly stable, research consistently shows that the gap is not in access to books but in maintaining the habit of finishing them — which is where the design choices in reading apps make a real practical difference.
64%
How People Are Reading — and What Helps It Stick
Libby
Digital library app focused on borrowing ebooks, audiobooks, and magazines from public libraries through a single reading platform.
Libby is a free digital library app developed by OverDrive, allowing anyone with a valid public library card to borrow ebooks, audiobooks, and magazines at no cost. It supports offline downloads, cross-device sync, adjustable playback speed for audiobooks, highlights and notes for ebooks, a built-in dictionary, and reading lists with tagging. Users in the US can also send borrowed ebooks directly to a Kindle device. The app is available on iOS, Android, and in web browsers, and works with thousands of public libraries worldwide.
Libby’s defining advantage is its zero cost. For any reader with a library card, it provides access to ebooks, audiobooks, and magazines with automatic returns, no late fees, and offline reading capability — all without a subscription. The borrowing experience is straightforward, the app is well designed, and its integration with Kindle devices makes it a practical bridge between the library system and a reader’s existing setup.
Libby’s primary limitation is availability and wait times. The catalogue is determined by the individual library’s licensing agreements, which means popular new releases can have queues of weeks or months. There are no daily reading goals, streaks, or gamified habit features — Libby is a borrowing tool, not a habit-building platform. Compared to Kindle, annotation support is present but less sophisticated. Compared to Moon+ Reader, there is no support for user-supplied ebook files in various formats. Compared to Scribd, the catalogue is less predictable but entirely free.
Best suited for cost-conscious readers who prefer ebooks and audiobooks and are comfortable planning their reading list around library availability.
Libby’s defining advantage is its zero cost. For any reader with a library card, it provides access to ebooks, audiobooks, and magazines with automatic returns, no late fees, and offline reading capability — all without a subscription. The borrowing experience is straightforward, the app is well designed, and its integration with Kindle devices makes it a practical bridge between the library system and a reader’s existing setup.
Libby’s primary limitation is availability and wait times. The catalogue is determined by the individual library’s licensing agreements, which means popular new releases can have queues of weeks or months. There are no daily reading goals, streaks, or gamified habit features — Libby is a borrowing tool, not a habit-building platform. Compared to Kindle, annotation support is present but less sophisticated. Compared to Moon+ Reader, there is no support for user-supplied ebook files in various formats. Compared to Scribd, the catalogue is less predictable but entirely free.
Best suited for cost-conscious readers who prefer ebooks and audiobooks and are comfortable planning their reading list around library availability.
Retention Improvement With Gamified Reading Tools
Research into reading engagement has found that gamified reading tools — those using streaks, goals, and progress tracking — can improve retention by up to 75% compared to unstructured reading. This finding points to something practical: the habit-supporting design of an app, not just its library size, is a meaningful factor in whether a reader actually finishes books and remembers what they read.
75%
U.S. Audiobook Market Revenue in 2024
According to data from the Association of American Publishers, the U.S. audiobook market reached $1.1 billion in revenue in 2024, growing by nearly 24% year-over-year. This rapid growth reflects a broader shift in how people consume books — with listening during commutes, exercise, and household tasks becoming a primary reading format for a growing share of adults.
$1.1B
U.S. Adults Who Read at Least One Book Last Year
Pew Research Center data from October 2025 found that 64% of U.S. adults read at least one book in the past year in any format. While this number has remained broadly stable, research consistently shows that the gap is not in access to books but in maintaining the habit of finishing them — which is where the design choices in reading apps make a real practical difference.
64%
How People Are Reading — and What Helps It Stick
Scribd
Digital subscription reading platform focused on ebooks, audiobooks, documents, magazines, and educational content in one library-style service.
Scribd — whose consumer reading service is now branded Everand — is a flat-rate subscription platform offering access to ebooks, audiobooks, magazines, and documents for a monthly fee. Its library spans hundreds of thousands of titles across both formats, and the subscription model means users can read or listen to as many titles as they choose without per-book costs. The app supports highlighting and bookmarking in ebooks, variable audiobook playback speed, a sleep timer, offline downloads, and personalised recommendations based on reading history.
Scribd’s clearest advantage is format breadth within a single subscription. Readers who switch regularly between ebooks and audiobooks — and who also read magazines or research documents — get all of that from one monthly payment, which at approximately $11.99 per month is cheaper than Audible’s premium plan. The recommendation engine improves over time as it learns a user’s tastes, which helps with book discovery.
The trade-offs are meaningful. Scribd’s audiobook catalogue for premium titles is smaller than Audible’s, and popular new releases are not always available. Some titles rotate in and out of availability. Access to all content ends when the subscription does, unlike Audible’s ownership model. The annotation tools for ebooks have received criticism for limited colour options and occasional sync issues. Compared to Libby, it is not free; compared to Kindle, the reading experience within the ebook reader is less polished; compared to Moon+ Reader, it does not support user-supplied files.
Best suited for mixed-format readers who want ebooks, audiobooks, and magazines available from one subscription without paying per title.
Scribd’s clearest advantage is format breadth within a single subscription. Readers who switch regularly between ebooks and audiobooks — and who also read magazines or research documents — get all of that from one monthly payment, which at approximately $11.99 per month is cheaper than Audible’s premium plan. The recommendation engine improves over time as it learns a user’s tastes, which helps with book discovery.
The trade-offs are meaningful. Scribd’s audiobook catalogue for premium titles is smaller than Audible’s, and popular new releases are not always available. Some titles rotate in and out of availability. Access to all content ends when the subscription does, unlike Audible’s ownership model. The annotation tools for ebooks have received criticism for limited colour options and occasional sync issues. Compared to Libby, it is not free; compared to Kindle, the reading experience within the ebook reader is less polished; compared to Moon+ Reader, it does not support user-supplied files.
Best suited for mixed-format readers who want ebooks, audiobooks, and magazines available from one subscription without paying per title.
Retention Improvement With Gamified Reading Tools
Research into reading engagement has found that gamified reading tools — those using streaks, goals, and progress tracking — can improve retention by up to 75% compared to unstructured reading. This finding points to something practical: the habit-supporting design of an app, not just its library size, is a meaningful factor in whether a reader actually finishes books and remembers what they read.
75%
U.S. Audiobook Market Revenue in 2024
According to data from the Association of American Publishers, the U.S. audiobook market reached $1.1 billion in revenue in 2024, growing by nearly 24% year-over-year. This rapid growth reflects a broader shift in how people consume books — with listening during commutes, exercise, and household tasks becoming a primary reading format for a growing share of adults.
$1.1B
U.S. Adults Who Read at Least One Book Last Year
Pew Research Center data from October 2025 found that 64% of U.S. adults read at least one book in the past year in any format. While this number has remained broadly stable, research consistently shows that the gap is not in access to books but in maintaining the habit of finishing them — which is where the design choices in reading apps make a real practical difference.
64%
How People Are Reading — and What Helps It Stick
Moon+ Reader
Lightweight Android eBook reader focused on deep reading customization and broad file compatibility.
Moon+ Reader is a highly customisable ebook reader for Android that supports an exceptionally wide range of file formats, including EPUB, PDF, MOBI, DJVU, AZW3, FB2, CBZ, CBR, TXT, and more. Unlike the other apps in this comparison, it works with files stored directly on a user’s device or connected cloud services, rather than requiring content to be purchased or borrowed from a platform. The Pro version adds an ad-free experience, reading statistics, PDF annotation, text-to-speech, cloud sync via Dropbox or WebDAV, and a reading ruler for focus reading.
Moon+ Reader’s main strength is its format versatility and annotation depth for power users. It is the only app in this group that can open virtually any ebook or document format a reader might already own, making it the strongest choice for users with large personal libraries in mixed formats. Its highlight and annotation system — including PDF annotation in the Pro version — is among the most detailed available on Android, and reading statistics in Pro track time spent and pages completed over time.
The limitations are practical. Moon+ Reader is Android-only and has no official iOS version, which immediately excludes a large portion of potential users. It does not include a built-in catalogue, subscription service, or book discovery layer — users bring their own content. The free version carries intrusive ads, and the learning curve for new users unfamiliar with ebook file management can be steep. Compared to Kindle, it offers more format flexibility but no ecosystem or purchasing integration. Compared to Audible, it lacks audio support. Compared to Libby and Scribd, it requires the user to source their own content.
Best suited for Android users with existing ebook collections in multiple formats who want detailed annotation tools and a fully customisable reading environment.
Moon+ Reader’s main strength is its format versatility and annotation depth for power users. It is the only app in this group that can open virtually any ebook or document format a reader might already own, making it the strongest choice for users with large personal libraries in mixed formats. Its highlight and annotation system — including PDF annotation in the Pro version — is among the most detailed available on Android, and reading statistics in Pro track time spent and pages completed over time.
The limitations are practical. Moon+ Reader is Android-only and has no official iOS version, which immediately excludes a large portion of potential users. It does not include a built-in catalogue, subscription service, or book discovery layer — users bring their own content. The free version carries intrusive ads, and the learning curve for new users unfamiliar with ebook file management can be steep. Compared to Kindle, it offers more format flexibility but no ecosystem or purchasing integration. Compared to Audible, it lacks audio support. Compared to Libby and Scribd, it requires the user to source their own content.
Best suited for Android users with existing ebook collections in multiple formats who want detailed annotation tools and a fully customisable reading environment.
Retention Improvement With Gamified Reading Tools
Research into reading engagement has found that gamified reading tools — those using streaks, goals, and progress tracking — can improve retention by up to 75% compared to unstructured reading. This finding points to something practical: the habit-supporting design of an app, not just its library size, is a meaningful factor in whether a reader actually finishes books and remembers what they read.
75%
U.S. Audiobook Market Revenue in 2024
According to data from the Association of American Publishers, the U.S. audiobook market reached $1.1 billion in revenue in 2024, growing by nearly 24% year-over-year. This rapid growth reflects a broader shift in how people consume books — with listening during commutes, exercise, and household tasks becoming a primary reading format for a growing share of adults.
$1.1B
U.S. Adults Who Read at Least One Book Last Year
Pew Research Center data from October 2025 found that 64% of U.S. adults read at least one book in the past year in any format. While this number has remained broadly stable, research consistently shows that the gap is not in access to books but in maintaining the habit of finishing them — which is where the design choices in reading apps make a real practical difference.
64%
How People Are Reading — and What Helps It Stick
Choosing the Reading App That Matches How You Actually Read
Kindle and Moon+ Reader sit at the top of this comparison for annotation and retention tools, but they serve different users: Kindle within the Amazon ecosystem with a polished integrated experience, and Moon+ Reader for Android readers managing their own libraries who need deep format support and customisation. Audible stands on its own as the format-specific choice for audiobook listeners who value catalogue breadth and permanent ownership over a flat-rate subscription. Libby and Scribd occupy the access-first category — Libby at no cost with library availability constraints, and Scribd at a flat monthly fee with broader on-demand reach but no permanent ownership.
The most useful question when choosing is not which app has the largest library, but which features support the way a particular reader actually reads. A listener who absorbs books during a commute needs a different tool than a reader who annotates non-fiction for later review. Many readers find that combining two apps — a catalogue source like Libby or Scribd alongside a more feature-rich reader like Kindle — gives them the best of both: broad access and genuine retention support.
Good To Knows:
• Annotation and highlighting tools vary significantly between apps — Kindle and Moon+ Reader offer the most detailed marking and note-taking systems, while Audible’s audio format naturally limits what can be annotated during listening.
• Format support matters more than most people expect: apps like Moon+ Reader can open EPUB, PDF, MOBI, DJVU, and many other file types from a user’s own storage, while Kindle and Audible are primarily tied to content purchased through Amazon.
• Libby is entirely free for anyone with a public library card, including ebooks, audiobooks, and magazines — making it the lowest-cost entry point in this comparison with no subscription required.
• Scribd (now branded Everand for its consumer reading service) offers both ebooks and audiobooks under one flat monthly subscription, but the audiobook catalogue for premium titles is smaller than Audible’s, and access ends when the subscription does.
• Kindle’s Whispersync for Voice allows users to switch between reading an ebook and listening to the matching audiobook without losing their place — a useful feature for readers who want to move between formats depending on the situation.
Where These Five Apps Differ and Why It Changes What You Get Out of Reading
• Kindle’s ecosystem depth is unmatched: highlights and notes sync across every device, can be exported, and integrate with the Immersive Reading feature that highlights ebook text in sync with a paired audiobook narration — a feature no other app in this group replicates.
• Audible is the largest dedicated audiobook platform, with a catalogue significantly larger than Scribd’s and a credit-based model that means purchased titles are owned permanently, not lost when a subscription ends.
• Libby’s biggest limitation is availability — since the catalogue depends on what each library has licensed, popular titles can have long wait times, making it less predictable for readers who want immediate access to specific books.
• Moon+ Reader Pro supports the widest range of file formats of any app in this comparison, making it the strongest choice for users with existing ebook collections in multiple formats, including PDFs, DRM-free files, and comic formats.
• None of the five apps include spaced repetition natively — users who want to actively review and retain what they read need to either export highlights to a separate tool or build their own review system alongside the reading app.
App Comparisons:
Apps 🠛
Annotation & Retention Tools
Format & Library Breadth
Habit-Building Features
Kindle
5/5
4/5
3/5
2/5
1/5
4/5
5/5
3/5
2/5
1/5
5/5
4/5
3/5
2/5
1/5
Audible
5/5
4/5
3/5
2/5
1/5
4/5
5/5
3/5
2/5
1/5
5/5
4/5
3/5
2/5
1/5
Libby
5/5
4/5
3/5
2/5
1/5
4/5
5/5
3/5
2/5
1/5
5/5
4/5
3/5
2/5
1/5
Scribd
5/5
4/5
3/5
2/5
1/5
4/5
5/5
3/5
2/5
1/5
5/5
4/5
3/5
2/5
1/5
Moon+ Reader
5/5
4/5
1/5
Related Science: ⮛
Related Gadgets: ⮛
Did You Get That?
What is Whispersync for Voice and which apps use it?
Whispersync for Voice is an Amazon feature that keeps a user’s reading position synchronised between the Kindle ebook and the matching Audible audiobook, so switching between reading and listening never loses the reader’s place. It works across the Kindle and Audible apps and requires both the ebook and audiobook to be owned on the same Amazon account.
Is Libby really free, and what is the catch?
Libby is completely free to use with a valid public library card — there are no subscription fees, in-app purchases, or late fines since borrowed titles return automatically on their due date. The main limitation is that availability depends entirely on what each library has licensed, meaning popular titles can have wait times of several weeks.
What is the difference between Scribd and Everand?
Scribd rebranded its consumer reading service — ebooks, audiobooks, and magazines — as Everand in 2023, while the Scribd name now refers primarily to its document-sharing platform. The content library and pricing are the same; Everand is simply the current name for the subscription reading app most people associate with Scribd.
Does Moon+ Reader work on iPhone?
Moon+ Reader is Android-only and does not have an official iOS version. iPhone and iPad users looking for a feature-rich ebook reader with strong annotation support should consider Kindle, which is available across both platforms.
Which app is best if I switch between reading and listening throughout the day?
Kindle paired with Audible offers the most seamless experience for switching between formats, using Whispersync to keep position aligned across both. For a single-subscription option covering both formats, Scribd provides ebooks and audiobooks together, though its audiobook catalogue for premium titles is smaller than Audible’s.
Other Related Apps ⮛
Final Summary
Each of the five apps in this comparison solves a different part of the reading habit problem. Kindle is the most complete ecosystem for ebook readers who want highlights, vocabulary building, reading streaks, and the option to pair books with Audible narration. Audible is the strongest dedicated audiobook platform, with the largest catalogue and the security of permanent ownership. Libby removes the cost barrier entirely for anyone with a library card, making it the most accessible starting point for readers who do not need immediate access to specific titles. Scribd offers the broadest format mix — ebooks, audiobooks, and magazines — under one subscription, which suits readers who consume content across multiple formats regularly. Moon+ Reader is the most technically capable reader in the group for Android users, particularly those with diverse personal libraries who need deep file format support and annotation control.
The common thread is that reading more consistently is as much a design problem as a motivation problem. Apps with daily goals, streaks, and integrated retention tools create more friction against stopping — and Kindle does this better than any other app here. For listeners, Audible’s reliability does the same. Choosing an app that is designed around the reader’s actual format and habit preferences is the most practical step toward reading more and remembering what was read.
Don't Know What to Choose?
Best app for building a reading habit with annotation and retention tools: Kindle
Kindle’s combination of daily reading goals, reading streaks, highlights that sync across all devices, vocabulary builder, and Immersive Reading mode makes it the most complete tool for readers who want to read consistently and retain more of what they read.
Best app for free access to ebooks and audiobooks: Libby
Libby requires only a valid public library card and no subscription fee, giving readers free access to ebooks, audiobooks, and magazines with automatic returns and no late fees.
Best app for Android users with mixed-format personal ebook libraries: Moon+ Reader
Moon+ Reader Pro supports the widest range of ebook and document formats of any app in this comparison, making it the strongest choice for readers who own files in multiple formats and want detailed annotation and customisation tools.
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