Comparison

Bookends vs Paperpile

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Bookends

Manage your research references and PDFs on your mobile device. Search online databases, import metadata, annotate PDFs, and organize your library. Offers basic functionality for free with optional one-time purchase and yearly subscription for advanced features like cloud sync and unlimited imports.

Highlights
  • Search online reference databases
  • Import metadata and PDFs
  • PDF annotation and markup
  • Barcode scanning for references
  • Cloud sync across devices
  • Share online libraries
  • Create multiple libraries
Features
Read full description

Bookends is the reference management app you've been looking for. The basic version offers: • Search online sites directly (arXiv, Google Books, Google Scholar, JSTOR, the Library of Congress, PubMed, PubMed Central, and Semantic Scholar) or use the built-in browser (EZProxy-compliant) to download reference metadata and PDFs (access privileges required). Searches can return a maximum of 20 references, and only 50 references can be stored in your personal database. • Use unique identifiers such as DOI, PMID, ISBN, or arXiv id to autofill references. • View the text of PDF annotations in a note stream, and create your own with our powerful PDF markup engine. • Barcode scanning, one per day. • And many more features designed to help you discover, organize, and use reference information. Standard, one-time purchase ($14.99): • No limit on searches or importing. Premium, yearly subscription ($14.99). Requires a Standard purchase. • Cloud sync with all your iOS devices and Bookends for Mac (separate purchase). • Share online libraries with colleagues. • Scan documents with Mellel Mobile*. • Create multiple libraries. • Unlimited barcode scanning. • Extract PDF annotations with deep links to annotations and text. • Convenient UI to add PDF notes to the library. • Automate your actions with Shortcuts. * iPad-only. Requires a Mellel Mobile Premium subscription. Subscription is for one year and has an auto-renew option. The subscription can be managed in iOS -> Settings > [your name] > Subscriptions. A subscription will renew if it isn't canceled at least 24 hours before the renewal date. If the subscription is not renewed, Premium will be disabled but Standard will continue to work. Terms of Service: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

Paperpile

Organize and manage your research papers effortlessly. Collect, read, and annotate PDFs from millions of academic journals. Beat paper chaos with a tidy digital library.

Highlights
  • Search millions of academic papers
  • Collect PDFs with one tap
  • Organize with folders and labels
  • Read and annotate PDFs
  • Highlight and add notes
  • Browser integration for saving
Features
Read full description

Get a head start for you research and finally beat the paper chaos on your desk. With Paperpile you have all your research PDFs in one place — nice and tidy. Paperpile makes it easier than ever to collect, manage, read, and annotate your papers. FIND & COLLECT - Search millions of papers from 20,000+ academic journals right in the app. - Add new papers to your collection with one tap and the PDF will be downloaded automatically. - Save directly from your browser to your Paperpile library - User your university's off-campus proxy access to get restricted content behind paywalls. MANAGE & ORGANIZE - Bring structure to your library with folders and subfolders - Organize your library visually with colored labels - Mark important papers with stars. - Search your library to find the paper you need fast. READ & ANNOTATE - Read like on paper with a fast and slick PDF viewer experience - Highlight important sections in different colors - Add notes and never forget an important idea. - Add hand-drawn annotations - with your fingers or your Apple Pencil The Paperpile App requires a Paperpile account.

Screenshots

Bookends4 screens
Paperpile3 screens

Verdict

The call

The clearest difference is in-app purchases: Paperpile at none against Bookends's 2. Paperpile also leads on iOS requirement (12.0 vs 17.6). Bookends's advantage is rating (4.7 vs 4.5) and ratings volume (394 vs 129). On price, review sentiment, update cadence and ads 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Bookends sells 2 in-app purchases, starting at $14.99 per year. Paperpile asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Bookends holds the better App Store score, 4.7 against 4.5. Both are backed by a comparable volume of ratings — 394 and 129 respectively. Written reviews point the same way: 76% of Bookends's written reviews are positive against 72% of Paperpile's.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on August 28, 2026 and September 21, 2026 respectively.

Scorecard5 real differences · 5 level
Bookends versus Paperpile: the parameters behind the verdict, then further details
ParameterBookendsPaperpile
PriceFreeFree
Rating4.7 (394 ratings) — better4.5 (129 ratings)
Positive reviews76.4% of reviews — better71.6% of reviews
Number of ratings394 — better129
Update frequencyEvery 2 monthsEvery 2 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS17.612.0 — better
Further details — not scored
Size111 MB242 MB
Age rating4+4+
DeveloperSonny Software, LLCPaperpile LLC

Customer experience

Bookends

All ratings394 ratings
Positive92.1%
Neutral2.3%
Negative5.6%
Written reviews127 reviews
Positive76.4%
Neutral8.7%
Negative15.0%

Paperpile

All ratings129 ratings
Positive86.8%
Neutral3.9%
Negative9.3%
Written reviews81 reviews
Positive71.6%
Neutral4.9%
Negative23.5%

User reviews

Bookends

From 394 App Store ratings

What we love

  • 🚀 Seamless sync across devices
  • 👍 Excellent PDF annotation tools
  • 🔒 Reliable and stable
  • 💡 Powerful reference management features
  • 👍 Responsive and helpful developer support

Room to improve

  • 🐛 Sync issues with iCloud and PDF files
  • 🔒 Subscription model for essential features
  • 👎 Outdated and clunky user interface
  • 🔒 Limited functionality on iOS without subscription

Paperpile

From 129 App Store ratings

What we love

  • 👍 Excellent reference library management
  • 🔄 Seamless cross-device synchronization
  • ✍️ Intuitive PDF annotation and highlighting
  • 🎨 Clean and minimalist user interface
  • 📱 Strong iPad and mobile integration

Room to improve

  • 🐛 Frequent crashes and instability
  • ⏱️ Lack of updates for extended periods
  • 📱 Mobile app significantly behind web version features
  • 🔋 High battery drain on iPad
  • 🌙 No dark mode support

Bugs and requests

Bookends

Reported bugs

3 issues
  • Incompatibility with iCloud Optimized Storage
  • Unreliable sync between desktop and mobile versions
  • Occasional data loss or corruption

Requested features

4 requests
  • Nested folders and tags for better organization
  • Automatic PDF metadata extraction
  • Improved search and filtering capabilities
  • Seamless integration with third-party services

Paperpile

Reported bugs

12 issues
  • App crashes frequently on iPad and iOS devices
  • Highlighting disappears when revisiting papers
  • Overlapping annotations delete together when removing one
  • Sync failures requiring logout/login cycles
  • Annotations not syncing between iPad and web versions
Show 7 more
  • PDF metadata recognition failures when adding papers
  • Settings reset when returning to previously edited files
  • App incompatible with older iOS versions (iOS 12)
  • Login authentication errors with university accounts
  • App crashes without reliable internet connection
  • Search functionality broken after updates
  • Annotations not saving/loading on iOS 14.4.2

Requested features

17 requests
  • Dark mode implementation
  • Edit citation metadata on mobile app
  • Change PDF file functionality
  • Save to downloads feature
  • Dictionary/lookup function for reading
Show 12 more
  • Cite while you write feature
  • BibTeX export capability
  • Ability to upload PDFs directly from mobile app
  • Support for Safari and other browsers
  • Desktop application version
  • Shared library access in mobile app
  • Advanced sorting options (by title, author, date)
  • Custom color options for annotations
  • Paste images into PDFs
  • Shape snapping for drawing tools
  • University email authentication
  • Paper rating system beyond stars

In-app purchases

2 purchases

Bookends

Subscriptions1
  • Premium3 Months trial$14.991 Year
One-time1
  • Standard$14.99
None

Paperpile

No in-app purchases

Questions

Is Bookends free?
Bookends is free to download, with in-app purchases available.
Is Paperpile free?
Paperpile is free to download, with no in-app purchases.
Which has better reviews, Bookends or Paperpile?
Bookends is rated higher. Bookends averages 4.7 out of 5 from 394 ratings, while Paperpile averages 4.5 from 129 ratings.
Do Bookends or Paperpile have ads?
Neither Bookends nor Paperpile shows ads.
Which is updated more often, Bookends or Paperpile?
Bookends ships an update every 2 months, and Paperpile every 2 months. Most recently, Bookends was updated on August 28, 2026 and Paperpile on September 21, 2026.

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