Same songs, every shuffle? Crankshaft reads the volume, the skips, the ones you let finish. Buttons exist, but the engine never waits for one. Nothing leaves your phone.
Crankshaft learns your taste from how you actually listen — how you move the volume, when you skip, what you let run to the end.
Full CarPlay support, which is where it makes the most sense: hands busy, eyes on the road, so what you do to a song actually means something.
Requires an active Apple Music subscription — Crankshaft plays through your existing Apple Music library. No separate account, no sign-up, and Crankshaft never sends your listening data anywhere. It stays on your device unless you choose to export it.
Most music apps only know what you tell them. Crankshaft takes that too — crank a song you love, freeze one you never want to hear again — and then it reads everything else: the volume you reach for, the song you kill at four seconds, the one you let run all the way to the end. Those signals cost you nothing to give, and nearly every other app throws them away. Every session shapes a living profile of your taste that gets sharper over time.
Give it real sessions and you'll feel the difference within a week. The app is free, you just bring your own Apple Music. The data is all yours, so there's no risk to you.
HOW IT WORKS
Crankshaft sits on top of your Apple Music library. Hit Ignite and it plays from your personal affinity ledger: a behavioral map of every song, scored by how you actually interacted with it. Crank the volume on a song you love and it learns. Skip something in the first ten seconds and it learns that too. Let a song play to the end and that quiet signal counts. Five behavioral zones, from instant skip to full completion, score every track on a curve. Buttons when you want them, physics the rest of the time.
IT PLAYS LIKE A STATION YOU CAN STEER
Crankshaft doesn't shuffle. It holds a mood — an era, a genre, an energy — the way a great radio station does, and keeps it there until you signal you want to move. Skip to steer: nudge it toward a different sound and it follows you down the rabbit hole; leave it alone and it holds the vibe. It's built to walk you around your own library, not loop your ten favorites.
REACH BEYOND WHAT YOU OWN
Declare the artists you love — even ones your library never captured — and Crankshaft opens their catalog and works them into your rotation. A single discovery dial sets how adventurous the engine gets, from comfortable and familiar to wide-open exploration.
FEATURES
The Crank — Turn up the volume with intent and Crankshaft feels it. That one gesture tells it more than a like ever could.
Affinity Ledger — Every song earns a score from real listening behavior. Scores rise and fall with your habits, not just your clicks.
CarPlay — Full CarPlay integration with Crank, Freeze, Up Next and Parent Mode controls on the dash.
Station & Drift — Crank a song and Crankshaft builds a station around that vibe, holding it and drifting naturally through your library and the Apple Music catalog.
Declared Artists — Name the artists you love and Crankshaft reaches their whole catalog, even music you don't own yet.
Discovery Dial — Blend new and unfamiliar music into your rotation at exactly the level you choose.
Pick an Album — On-demand album picks drawn from your affinity ledger, weighted toward what you love with a wildcard from deep in your library.
Parent Mode — A completely separate universe with its own ledger, scoring, and visual theme. Your kids' listening never touches your profile.
Road Trip Mode — A pre-cached 60-track queue built for long drives. Works offline.
PRIVACY BY DESIGN
Your data stays on your device. Crankshaft has no cloud sync, no ad targeting, no social graph, and no tracking pixels. Your affinity ledger lives in your app's local storage and never leaves your phone. Built on Apple MusicKit.
Like pandora for Apple Music without record labels defining what I’ll listen to next. I hear so many fewer repeat songs and find so much new music.The interface could use some work as IOS doesn’t seem to fully recognize it. Like when I get a phone call music doesn’t play or on the CarPlay interface there’s no indicator for the music playing so you don’t know how much is left. I’d love a single button that just adds songs to a playlist to my Apple Music favorites right from the now playing screen separate or integrated into the crank button. Otherwise, it’s great and does what I want better than Apple Music. Plus it’s free for now..
Developer Response
Thanks for this my friend, my friend.The playlist one you can use right now - every time you crank a song, Crankshaft files it in a playlist called Crankshaft Cranks in your Apple Music library. If nothing is showing up, check your settings (gear, phone screen top left) and make sure “Allow Crankshaft to save” is switched on. Apple Music’a Favorites heart is not something a third party app is allowed to set, so a playlist is as close as I can get right now.The phone call issue is real and fixed in the next update - “music not restarting after a phone call” is something I thought I had already fixed, but this brought it back up. That should be fixed but let me know if you have issues. The CarPlay progress bar is a problem I’m trying to fix, too. Crankshaft was telling the system that the song was playing at zero speed, so the bar had nothing to advance from. I’m going to keep chipping away at this one.Thanks again.
Interesting implementation
PhilM543
This app provides a novel approach to playing good music from your library
Developer Response
Thanks! Novel was what I was hoping for, that’s awfully nice of you to say. Crankshaft reads how you actually listen instead of asking you to rate everything (double thanks for taking the time to write this, in context).If you hit anything you don’t like, I’m all ears, this is a one-person project, real feedback shapes it directly. Thanks for giving it a try! -Justin
Playlists, all in one place.
New Playlists screen in Settings. What the engine reads from and what Crankshaft writes back now live together, instead of sitting three taps apart in two different sections.
New switch: tell Crankshaft not to write playlists at all. Your cranks still teach the engine. Nothing lands in your library.
Road Trip Mode is gone. It could never really download music, because Apple does not let other apps do that, and while it ran it quietly switched the engine off. The knob should be steering. Especially in the car.
Fixed: saving recent picks created a brand new playlist every time. There is one Crankshaft Saves list now, and it gets added to.
Fixed: with more than a hundred playlists, Crankshaft could only see the first hundred. It sees all of them now.
Fixed: Crankshaft could count its own playlists as music you curated. It no longer reads its own output back as your taste.
Fixed: No Remix forgot itself on every launch.
Version 1.8
The developer, Crankshaft LLC, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Privacy practices may vary, for example, based on the features you use or your age. Learn More
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
Seller
Crankshaft LLC
Size
7.4 MB
Category
Music
Compatibility
Requires iOS 17.5 or later.
iPhone Requires iOS 17.5 or later.
iPad Requires iPadOS 17.5 or later.
Mac Requires macOS 14.5 or later and a Mac with Apple M1 chip or later.
Apple Vision Requires visionOS 1.2 or later.
Languages
English
Age Rating
13+
13+
This app is rated 13+ with content restrictions.
Some content may be rated higher, and may therefore be restricted and managed by the developer through in-app controls.