Comparison

Spine vs Sutra

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

Head to head
About

Spine

This app enhances audiobook listening with features like listener levels, daily streaks, and shareable year-end recaps. It offers a beautiful, integrated player and syncs with Hardcover, all while keeping your data private on-device.

Highlights
  • Integrated audiobook player
  • Listener levels and daily streaks
  • Hardcover sync
  • On-device AI summaries
  • Shareable year-in-review recap
  • Lock screen and widget controls
Features
Read full description

Spine is the audiobook app you'll actually leave open. It streams from your own cloud library, syncs with Hardcover, and turns the habit of listening into something worth coming back to with listener levels, daily streaks, and a year-in-review Recap bright enough to share. Built native for iOS 26, with Liquid Glass, serif typography, and a player carved into the book's detail page. No subscription. No ads. No in-app purchases. No account to create with us. Bring your own library, keep your own data. WHAT MAKES IT DIFFERENT • ONE PAGE FOR THE BOOK: No separate Now Playing screen. Cover, scrubber, transport, speed, sleep timer, chapters, and bookmarks all live inline on the detail page, on an ambient backdrop tinted by the cover. • CHAPTERS THAT JUST WORK: Single-file M4B audiobooks expose their chapters automatically. Cloud folders with multiple M4Bs split into separate library entries. No manual editing, no reprocessing. • HARDCOVER SYNC: Just listen. Spine logs progress and finished books to Hardcover, pulls cover art, genre, and structured series data, and keeps your shelves in sync. • ON-DEVICE INTELLIGENCE: Open the next book in a tracked series and Spine writes a two-sentence "previously on…" recap from what you've already finished. It also rewrites bloated marketing descriptions into a calm summary, captions your Recap, and cleans up filename-salad titles. All on Apple's on-device foundation model. Nothing about your library leaves the phone. • LEVELS, STREAKS, AND GOALS: Lifetime hours unlock six tiers, from Sapling to Oracle. A unified daily/yearly goal card, a streak chip, and a year-spanning heatmap show the shape of your habit at a glance. • A RECAP YOU'LL WANT TO SHARE: Five bright screens covering hours, finished books, top author and genre, monthly rhythm, and the books you marked Read on Hardcover. One tap stitches the whole thing into a postable image. • PLAYBACK THAT PAYS ATTENTION: Step away for a moment and Spine rewinds a few seconds when you press play. The sleep timer fades audio gently to zero. Finish a series entry and the next book surfaces automatically. • LIVE ON THE LOCK SCREEN: Live Activities follow the current book onto the Lock Screen and Dynamic Island, with a tappable Play/Pause. The home-screen widget mirrors the same control on a cover-tinted backdrop, toggle playback in one tap, even when Spine isn't running. • BOOKMARKS WORTH KEEPING: Tap to mark any moment with a written note. Tap to jump back later. • SEARCH THAT POINTS SOMEWHERE: Open the search tab cold and you get a trending-genre card tuned to what you actually listen to, a Discover list of Audible new releases, and trending shortcuts. Most people aren't searching their own shelf, they're looking for the next thing. • EVERY BOOK IS A DOORWAY: Detail pages carry "More by author", "Top in genre", and a "Part of {Series}" rail that interleaves the books you own with the Hardcover siblings you don't, in reading order, right under your bookmarks. • CLOUD LIBRARY, REPAIRED IN ONE TAP: When a cloud title expires or goes stale, Spine flags it on the detail page and offers a one-tap re-download. No re-adding, no losing your progress. • SPOTLIGHT-INDEXED: Search your library from anywhere in iOS. PRIVACY BY DEFAULT Spine has no servers, no analytics, and no third-party SDKs. API keys live in the iOS Keychain. Your library, listening history, and bookmarks stay on your device (and sync via your own iCloud, if you enable it). The on-device AI features run on Apple Intelligence — your books never leave the phone. REQUIREMENTS • iPhone running iOS 26. • A cloud audiobook library. • A free Hardcover account is recommended for metadata, search, and read sync. • Apple Intelligence-eligible device is required for the optional AI features (everything else works without it).

About

Sutra

Access your entire book collection from various sources in one beautiful app. Enjoy a customizable reading experience with synced progress, bookmarks, and highlights across devices. Organize your library with series info, search, and collections.

Highlights
  • Connect Kavita, Calibre, and OPDS servers
  • EPUB and PDF reading with page-curl effect
  • Rich typography and reading themes
  • iCloud sync for progress, bookmarks, and highlights
  • Offline downloads
  • Highlighting and search functionality
  • Series grouping and collections
Features
Read full description

Sutra is a warm, thoughtful home for every book and comic you love. Bring together your self-hosted library, your manga, your classic EPUBs, and those “just one more chapter” reads in one beautifully calm reader. Connect Kavita, Komga, or Calibre; explore any OPDS catalogue; or discover a new favourite from Project Gutenberg and Standard Ebooks. READ YOUR WAY • Enjoy EPUB, PDF, CBZ, MOBI, fixed-layout comics, and manga in one place • Move through comics panel by panel, or take in the whole page • Read right-to-left manga and beautiful iPad two-page spreads • Make the page yours with fonts, text size, spacing, themes, auto-scroll, page turns, and Sutra-only brightness control A LIBRARY THAT FEELS LIKE HOME • Browse dedicated Series and Collection views, with Favorites always close by • Sort by Recently Read, Title, Author, or Date Added while staying in a familiar cover grid • Let Sutra recover missing Calibre series details and keep your library beautifully organised • Pick up where you left off with dependable progress and finished-book sync for Kavita and Komga BUILT FOR SELF-HOSTERS • Connect Kavita, Komga, Calibre, Grimmory, or another OPDS server • Stream comic pages from Kavita and Komga when available, or download for offline reading • Keep your highlights and reading progress with you across your Apple devices Sutra is free to enjoy for EPUB and PDF reading, with no ads and no subscription. Unlock unlimited CBZ, MOBI, and Komga reading once, and keep it forever.

Screenshots

Spine4 screens
Sutra4 screens

Verdict

The call

The clearest difference is rating: Spine at 4.8 against Sutra's 4.3. Spine also leads on in-app purchases (none vs 4) and review sentiment (86% vs 73%). Sutra's advantage is iOS requirement (17.0 vs 26.0). On price, ratings volume, 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. Sutra sells 4 one-off in-app purchases. Spine asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Spine holds the better App Store score, 4.8 against 4.3. Both are backed by a comparable volume of ratings — 30 and 17 respectively. Written reviews point the same way: 86% of Spine's written reviews are positive against 73% of Sutra's.

UpkeepUpdate frequency

Spine ships an update every 4 days, Sutra weekly. Both last shipped on October 25, 2026.

Scorecard4 real differences · 6 level
Spine versus Sutra: the parameters behind the verdict, then further details
ParameterSpineSutra
PriceFreeFree
Rating4.8 (30 ratings) — better4.3 (17 ratings)
Positive reviews85.7% of reviews — better73.3% of reviews
Number of ratings30 — better17
Update frequencyEvery 4 days — betterWeekly
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFreeFree
DevicesiPhone, Apple WatchiPhone, iPad
Requires iOS26.017.0 — better
Further details — not scored
Size15 MB42 MB
Age rating12+4+
DeveloperAccelyze Inc.Koustav Dasgupta

Customer experience

Spine

All ratings25 ratings
Positive96.0%
Neutral4.0%
Negative0.0%
Written reviews14 reviews
Positive85.7%
Neutral14.3%
Negative0.0%

Sutra

All ratings17 ratings
Positive76.5%
Neutral17.6%
Negative5.9%
Written reviews15 reviews
Positive73.3%
Neutral13.3%
Negative13.3%

In-app purchases

None

Spine

No in-app purchases

4 purchases

Sutra

One-time4
  • Small Tip$1.99
  • Medium Tip$2.99
  • Large Tip$4.99
Show 1 more
  • Sutra Pro$6.99

Questions

Is Spine free?
Spine is free to download, with no in-app purchases.
Is Sutra free?
Sutra is free to download, with in-app purchases available.
Which has better reviews, Spine or Sutra?
Spine is rated higher. Spine averages 4.8 out of 5 from 30 ratings, while Sutra averages 4.3 from 17 ratings.
Do Spine or Sutra have ads?
Neither Spine nor Sutra shows ads.
Which is updated more often, Spine or Sutra?
Spine ships an update every 4 days, and Sutra weekly. Most recently, Spine was updated on October 25, 2026 and Sutra on October 25, 2026.

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