Bent Spool
Tremolo, Repeat, Loops FX
Free · In‑App Purchases
Tremolo, pitched repeats and fragment loops with tape wear, as an AUv3 for AUM and GarageBand. Free to try; one $9.99 unlock, no subscription.
Bent Spool is a creative effect that can transform simple musical parts into unexpected rhythms and melodies, played live or as an effect in your favorite host app. Shape a tremolo pulse, turn a note into a run of pitched repeats, or build a moving layer from fragments of what you just played. Drive the input with built-in overdrive or fuzz, add a core effect, then finally layer in vintage analog tape effects.
THREE MODES
TREM: a pulsing volume effect, from a rounded sine through triangle and sawtooth to a hard square gate. Syncs to your host's tempo or runs free.
REPEAT: up to 64 pitched copies with their own decay and feedback, across five pitch stations from two octaves down to two octaves up.
LOOPS: up to six overlapping fragments of your recent audio, spread across pitch, direction, read position and the stereo field.
CHARACTER
CHAOS adds movement that suits each mode: octave jumps in REPEAT, held or stalled pulses in TREM, wandering reversals and pitch drift in LOOPS.
WEAR adds tape wear, magnetic saturation and digital crush after the active mode.
At the input, OD is a softer clip; FUZZ is a harder distortion that sputters as it decays.
PRESETS
48 factory presets: 10 TREM, 15 REPEAT, 15 LOOPS and an 8-preset Fuzz Tremolo pack. Unlock to save your own.
FREE TO TRY
TREM plays in full on the OD voice with ten presets. No time limit, no interruptions. A single $9.99 in-app purchase unlocks REPEAT, LOOPS, FUZZ, the rest of the presets and preset saving. No subscription.
Runs as a standalone app or as an AUv3 effect in AUM, Loopy Pro and other AUv3 hosts, on iPhone and iPad.
Ratings & Reviews
Controls are more reliable: fixed an intermittent problem where a control, most often the mode switch, stopped responding until a preset was changed.
Swipe the mode switch: slide along it to move between TREM, REPEAT and LOOPS, as well as tapping.
Knobs follow your finger: drag up or right to turn a knob up, down or left to turn it down, so a swipe no longer has to be straight up and down.
Octave direction for LOOPS: a new DIRECTION switch on the back panel sends the voices up only, down only, or both ways. Up only keeps every voice at or above the original pitch, so low octaves no longer muddy the sound.
Triplet sync: 1/16T, 1/8T, 1/4T and 1/2T note lengths in every mode when SYNC is on.
In wide host windows, such as AUM on a larger iPad, the pedal now sits centred instead of hugging the left edge.
The developer, Plastic Factory 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.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Plastic Factory LLC
- Size
- 23.7 MB
- Category
- Music
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - iPad
Requires iPadOS 17.0 or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Bent Spool Unlock $9.99
- Copyright
- © 2026 Plastic Factory LLC