Spine - Audiobook Player

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).