Spine streams from your cloud library, syncs with Hardcover, and rewards the habit — on-device "previously on…" catch-ups, listener levels, a bright year-in-review Recap, and a player crafted for Liquid Glass.
Every screen earns its place. No clutter, no ads, no algorithm guessing what you wanted to hear next.
Bring your own library. Spine talks to it over a clean REST API and plays your books straight from the cloud — no syncing rituals, no broken folder hierarchies.
Open the search tab cold and Spine offers a trending-genre card tuned to what you actually listen to, a Discover list of popular titles, and trending search shortcuts — all pulled live from Hardcover.
Single-file M4B audiobooks expose their chapters automatically — no manual editing, no waiting for cloud reprocessing. Skip, scrub and resume by chapter, the way it should always have worked. A cloud folder with multiple M4B files is auto-split into separate library entries.
Just listen to your books and Spine logs it to Hardcover. Cover art and metadata land automatically, so your library always looks complete.
Liquid Glass, serif typography, and a book detail page with the player carved into it. Native SwiftUI from the bottom up — no web shells.
Five dense, colorful screens covering hours, finished books, top author and genre, monthly rhythm, and the books you marked Read on Hardcover. Share or copy stitches the whole thing into one long, postable image.
Lifetime hours unlock six tiers — Sapling to Oracle. Daily and yearly goals share a single two-ring card with a unified picker, a streak chip rewards consistency, and a year-spanning heatmap shows the shape of your habit at a glance.
Step away for half a minute and Spine rewinds a few seconds when you press play. The sleep timer fades audio gently to zero. Finish a book in a tracked series and the next entry surfaces automatically.
Live Activities surface the current book on the Lock Screen and in the Dynamic Island, with a tappable Play/Pause button right there. The home-screen widget gets a cover-tinted backdrop and the same Play/Pause control — tap to toggle without opening the app, even when Spine has been force-quit.
Tap to mark any moment with a written note or a short voice memo recorded right there. Bookmarks live on the book's detail page with tap-to-jump and a clean share sheet.
Below your bookmarks, every book picks up two rows of suggestions: "More by {author}" pulled from Apple's audiobook catalogue and "Top in {genre}" pulled from Hardcover. Square covers with subtle shadows, ellipsized titles. Tapping a recommendation already in your library hops the paged detail straight to that book; anything new drops you into the AudiobookBay → cloud library flow.
"Previously on…" series catch-ups, two-sentence description rewrites, Recap captions, and a one-tap fix for messy filename titles — all generated by Apple's on-device foundation model. No accounts, no analytics, nothing about your library leaves the phone.
No separate Now Playing screen. Cover, scrubber, transport, speed, sleep, chapters, bookmark, voice boost — the whole player lives inline on the book detail page, on top of an ambient backdrop that picks up the cover's dominant colors.
Tap a book to open it, tap the mini-player to come back to it. The detail page is the player. Sleep timers and variable speed are right where they belong; no carousel of "discover" suggestions over your audiobook.
Drop in your cloud library API key, link your Hardcover account, any lookup preferences. Spine remembers; you don't have to come back.
No accounts to create with us, no sync conflicts, no settings tabs nested four deep. The whole control surface fits on one page — and stays out of your way for the rest of the year.
Cover, summary, series order, bookmarks, and the live player itself — all in a single scrolling page that pulls Hardcover metadata in the background. The colorScheme-aware ambient backdrop wraps everything from the title bar down through the transport controls.
Mark finished, edit metadata, download for offline, or remove from your cloud library — every action is one tap from the detail view.
Daily goal, lifetime tier, last-30-days bars, recently finished — and a "Now Serving" pill that drops you into the year's Recap.
Every metric is local. Spine never asks for an account, never phones home, and the level you've earned is yours to keep.
Bright, Resy-inspired screens — cover collage, time spent, time saved by faster playback, books finished, monthly rhythm, and the books you marked Read on Hardcover — stitched into one tall poster on tap.
The serif numerals and warm palette lift the whole thing out of "stat dump" territory. Copy to clipboard, share to anywhere.
Open the next book in a Hardcover-tracked series and Spine writes a two-sentence "previously on…" recap from the books you've already finished — entirely on-device, in the time it takes the cover art to settle.
The same model rewrites bloated marketing-style descriptions into a calm two-sentence summary (one tap flips back to the original any time the model gets weird), drops a witty caption on each Recap page, and turns filename salad like The_Fellowship__Tolkien__Unabridged_2007 into a clean title and author with one tap. Each feature toggleable; nothing leaves the phone.
A Live Activity follows the current book onto the Lock Screen and into the Dynamic Island — cover, title, author, chapter, progress, and a tappable Play/Pause button.
The Continue Listening home-screen widget mirrors the same controls with a cover-tinted backdrop, so toggling playback is a single tap from the home screen — even if Spine isn't running. A Control Center button (and a Lock Screen toggle on iOS 18+) means the fastest path back to your audiobook is sometimes a single swipe.
Most people aren't searching their own shelf — they're looking for the next thing. So the search tab opens with a trending-genre card tuned to the genres you actually listen to, a Discover list of popular titles, and a few trending search shortcuts.
The placeholder rotates daily — "Search for your next journey", "Find a story to disappear into" — so it invites instead of describing. Type and your library matches surface first; AudiobookBay (when connected in Settings) extends the same query out to the broader catalogue.
The detail page picks up two recommendation rows under your bookmarks — "More by {author}" from Apple's audiobook catalogue, "Top in {genre}" from Hardcover. Square covers with subtle shadows, single-line titles, ellipsis when names get long.
Tapping a recommendation already in your library hops the paged detail directly to that book — no fresh sheet, no search round-trip, just a clean swipe. New titles drop you into the AudiobookBay → cloud library flow. Edit Metadata moved above About so the override sits one scroll away.
From the splash to the share card, the same warm restraint runs through it.
Yes. Spine reads your library through the Torbox REST API, so you'll need an active Torbox account and an API key. Pop it into Settings on first launch and Spine will pick up everything you already have.
Spine streams by default, so you don't have to manage local files. You can mark individual books as downloaded if you want offline access — they live alongside their cloud counterparts in the same library.
Hardcover provides clean book metadata and a great social reading layer. Spine pulls cover art, descriptions, and series info from Hardcover, and writes back read/finished status so your shelves stay in sync.
Not in v1. Spine is intentionally narrow — it does Torbox + Hardcover, well. Other backends are on the roadmap if there's demand.
Spine is iPhone-first on iOS 26. The codebase is SwiftUI-native, so iPad and Mac Catalyst are realistic future targets once iPhone is rock-solid.
Spine uses Apple's on-device foundation model (Apple Intelligence on iOS 26) for four specific things: writing a short "previously on…" recap when you start the next book in a tracked series, rewriting long marketing-style descriptions into two sentences, producing one-line captions on each Recap page, and cleaning up messy filename-derived titles. None of that leaves the phone. If your device isn't eligible for Apple Intelligence, Spine just falls back to its plain copy.
None. Spine talks to Torbox and Hardcover over their public APIs and that's it. No third-party SDKs, no event pipelines.
Join the TestFlight beta and help shape the player you'll keep open all year.