Shape is a polyphonic synthesiser allowing the user to draw the shape of the oscillator waveform. The first half of the oscillator is represented by 32 blocks and the second half is its mirror, generating all sorts of possible raw retroish sounds. 16 pages per oscillator allows to interpolate between different shapes. Add effects like arpeggio, stereo delay and a resonant filter and record your sounds on a classic tape. Modulate any parameter with keyboard, MIDI MPE or the device accelerometer. Connect to other apps with AudioBus, IAA, AUv3 and midi.

+++ 16 voice polyphony
+++ 2 oscillators, draw your own shape
+++ 3 oscillator mixing functions (add, subtract or multiply)
+++ Lfo modulation with ADSR: envelope, pitch, duty cycle, square, page or filter
+++ Record on tape with infinite overdubs (save, load, import, export)
+++ Arpeggiator
+++ Stereo delay
+++ Resonant filter (low, band and high pass)
+++ Modulate any parameter using keyboard, MIDI MPE or accelerometer (Built in or Sphero)
+++ Mini linear sequencer with euclidean rhythm
+++ On screen 25 key stylophone style keyboard
+++ AudioBus, Inter App Audio and AUv3
+++ Ableton link or AUv3 host sync
+++ CoreMIDI, IAA MIDI, Bluetooth MIDI, limited MPE and MIDI out
+++ Audio Paste, files app drag’n drop or open with

What’s New

Version 4.2.0

+++ Adding AUv3 support. Load shapesynth in your favourite host.
+++ Adding pages to oscillators. This allows to create 16 pages of oscillator shapes and interpolate between them.
+++ Adding ability to set negative oscillator values.
+++ Adding utility functions for modifying shape: shift right/left, double and halve.
+++ Adding cents settings in addition to octave, good for creating beating effects.
+++ Extending attack, decay and release times.
+++ Adding two new lfo modes, page and filter.
+++ Changing sequencer to only start playing on downbeat, not any division.
+++ Adding limited MPE support.
+++ Adding MIDI omni support.
+++ Adding bluetooth midi support.
+++ Adding hold to midi cc list.
+++ Adding midi out.
+++ Changing hold function. Clears notes whenever a new set of notes are pressed.
+++ Adding new modulation options: y absolute, y relative, midi brightness, midi pitchbend, midi pressure.
+++ Adding new presets.
+++ Changing tape record to initially record to loop point, press twice for continuous recording.
+++ Adding 12.5 ms anticlick envelope to tape (making it independent of tape speed).
+++ Adding support for viewing files in files app.
+++ Updating guide.
+++ Updating popover controllers.
+++ Improving delay buffer scaling.
+++ Resetting phase on repeated notes, stops clicking sound on short attacks.
+++ Adding fix for certain midi packages.
+++ Fixing midi cc adsr issue with.
+++ Fixing quirky attack test that was left in latest builds.
+++ Fixing issue with converting old adsr values to new format.
+++ Fixing issue with stuck sequencer when removing points before the current playhead.
+++ Fixing graphical issues with iOS 13, dark mode..
+++ Fixing iOS 13 fix that broke audio paste for iOS 12.
+++ Removing Akai SynthStation support.
+++ Removing Soundcloud support.

Ratings and Reviews

4.9 out of 5
9 Ratings

9 Ratings

Ben Efitofadoubt ,

Erik The Great does it again!

First class updates to a first class app from a first class developer.
Get them all! What are you waiting for?

Matreve ,

The last update turned it into a better app

I still wish the TAPE had both user definable loop end AND loop start points. Also, why does recording stop at the end of the loop when overdubbing? There should be an option for it to record continuously.

SynthyMiranda ,

Awesome Update!!!

I always loved the sound of Shapesynth, but could never wrap my head around the minimal and confusing interface. But this update basically restructures everything--it's virtually a new app. The developer has grown and grown, I think. His more recent apps like Elsa and Strng are brilliant, and I think all that experience has been applied to reinvent Shapsynth! So nothing but mad props from this girl! 😊


erik sigth
11.8 MB

Requires iOS 8.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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